diff --git a/src/main/kotlin/automaton/constructor/controller/TestsController.kt b/src/main/kotlin/automaton/constructor/controller/TestsController.kt
index c5b4106..15b9d5b 100644
--- a/src/main/kotlin/automaton/constructor/controller/TestsController.kt
+++ b/src/main/kotlin/automaton/constructor/controller/TestsController.kt
@@ -4,10 +4,13 @@ import automaton.constructor.model.automaton.Automaton
 import automaton.constructor.model.data.MemoryUnitDescriptorData
 import automaton.constructor.model.data.serializersModule
 import automaton.constructor.model.memory.MemoryUnitDescriptor
+import automaton.constructor.model.memory.Test
+import automaton.constructor.model.memory.TestsForSerializing
 import automaton.constructor.model.module.executor.ExecutionStatus
 import automaton.constructor.model.module.executor.Executor
 import automaton.constructor.utils.I18N
 import automaton.constructor.utils.addOnSuccess
+import automaton.constructor.utils.createExecutorAndRun
 import automaton.constructor.utils.runAsyncWithDialog
 import automaton.constructor.view.TestAndResult
 import automaton.constructor.view.TestsView
@@ -25,23 +28,21 @@ import kotlinx.serialization.modules.SerializersModule
 import tornadofx.*
 import java.io.File
 
-data class Test(val input: List<MemoryUnitDescriptor>)
-
-@Serializable
-data class TestsForSerializing(val tests: List<List<MemoryUnitDescriptorData>>, val automatonType: String)
-
 class TestsController(val openedAutomaton: Automaton) : Controller() {
     var wereTestsModified = false
+
     private val formatForSerializing = Json {
         serializersModule = SerializersModule {
             prettyPrint = true
             include(MemoryUnitDescriptorData.serializersModule)
         }
     }
+
     fun saveTests(tests: List<Test>, uiComponent: UIComponent) {
         val file = chooseFile(FileChooserMode.Save) ?: return
         saveAsync(tests, uiComponent, file)
     }
+
     private fun saveAsync(tests: List<Test>, uiComponent: UIComponent, file: File): Task<Unit> {
         return uiComponent.runAsyncWithDialog(
             I18N.messages.getString("TestsController.Saving"),
@@ -54,21 +55,31 @@ class TestsController(val openedAutomaton: Automaton) : Controller() {
             wereTestsModified = false
         }
     }
+
     fun createTests() {
         val testsWindow = find<TestsView>(mapOf(TestsView::controller to this))
         testsWindow.title = "Test"
         testsWindow.openWindow()
     }
+
     private fun chooseFile(mode: FileChooserMode): File? =
         chooseFile(
             filters = arrayOf(FileChooser.ExtensionFilter("1", "*.json")),
             mode = mode
         ).firstOrNull()
+
     fun openTests(uiComponent: UIComponent): List<Test> {
         val file = chooseFile(FileChooserMode.Single) ?: return listOf()
-        return openAsync(uiComponent, file).get()
+        val tests = openAsync(uiComponent, file).get()
+        return if (tests == null || !openedAutomaton.canUseTheseDescriptors(tests[0].input)) {
+            error(I18N.messages.getString("TestsController.UnableToOpen"))
+            listOf()
+        } else {
+            tests
+        }
     }
-    private fun openAsync(uiComponent: UIComponent, file: File): Task<List<Test>> {
+
+    private fun openAsync(uiComponent: UIComponent, file: File): Task<List<Test>?> {
         return uiComponent.runAsyncWithDialog(
             I18N.messages.getString("TestsController.Opening"),
             daemon = false
@@ -76,32 +87,26 @@ class TestsController(val openedAutomaton: Automaton) : Controller() {
             val deserializedTests =
                 formatForSerializing.decodeFromString<TestsForSerializing>(file.readText())
             if (deserializedTests.automatonType != openedAutomaton::class.simpleName!!) {
-                throw RuntimeException(
-                    I18N.messages.getString("TestsController.UnableToOpen")
-                )
+                null
+            } else {
+                deserializedTests.tests.map { test -> Test(test.map { it.createDescriptor() }) }
             }
-            deserializedTests.tests.map { test -> Test(test.map { it.createDescriptor() }) }
         } addOnSuccess {
             wereTestsModified = false
         }
     }
+
     fun runOnTests(tests: List<Test>) {
         val testsAndResults = mutableListOf<TestAndResult>()
         tests.forEach { test ->
             val memory = openedAutomaton.memoryDescriptors.zip(test.input).map {
                     (descriptor, content) -> descriptor.createMemoryUnit(content)
             }
-            val executor = Executor(openedAutomaton)
-            executor.start(memory)
-            executor.runFor()
-            val executionResult = when (executor.status) {
-                ExecutionStatus.ACCEPTED -> I18N.messages.getString("ExecutorController.Executor.Status.Accepted")
-                ExecutionStatus.REJECTED -> I18N.messages.getString("ExecutorController.Executor.Status.Rejected")
-                ExecutionStatus.FROZEN -> I18N.messages.getString("ExecutorController.Executor.Status.Frozen")
-                ExecutionStatus.RUNNING -> I18N.messages.getString("ExecutorController.Executor.Status.Running")
+            val executorResult = createExecutorAndRun(openedAutomaton, memory)
+            if (executorResult == null) {
+                return@runOnTests
             }
-            val graphic = executor.acceptedExeStates.firstOrNull()?.let { executionLeafView(it) }
-            testsAndResults.add(TestAndResult(test, executionResult, graphic))
+            testsAndResults.add(TestAndResult(test, executorResult.executionResult, executorResult.graphic))
         }
         val testsResultsWindow = find<TestsResultsFragment>(mapOf(TestsResultsFragment::testsAndResults to testsAndResults))
         testsResultsWindow.title = "Tests results"
diff --git a/src/main/kotlin/automaton/constructor/controller/module/executor/ExecutorController.kt b/src/main/kotlin/automaton/constructor/controller/module/executor/ExecutorController.kt
index 58d4c33..c50dd76 100644
--- a/src/main/kotlin/automaton/constructor/controller/module/executor/ExecutorController.kt
+++ b/src/main/kotlin/automaton/constructor/controller/module/executor/ExecutorController.kt
@@ -1,12 +1,11 @@
 package automaton.constructor.controller.module.executor
 
 import automaton.constructor.model.automaton.Automaton
-import automaton.constructor.model.module.executor.ExecutionStatus.*
 import automaton.constructor.model.module.executor.Executor
 import automaton.constructor.model.module.executor.SteppingStrategy
-import automaton.constructor.model.module.problems
 import automaton.constructor.utils.I18N
-import automaton.constructor.view.module.executor.executionLeafView
+import automaton.constructor.utils.createExecutorAndRun
+import automaton.constructor.utils.getNewExecutorOrNull
 import tornadofx.*
 
 class ExecutorController(viewedAutomaton: Automaton, private val uiComponent: UIComponent) : Controller() {
@@ -20,40 +19,20 @@ class ExecutorController(viewedAutomaton: Automaton, private val uiComponent: UI
             it.automaton.clearExecutionStates() // faster analog of executor.stop()
             debuggingExecutor = null
         } ?: run {
-            val executor = startNewExecutorOrNull() ?: return@toggleRun
-            executor.runFor()
-            val executionResult = when (executor.status) {
-                ACCEPTED -> I18N.messages.getString("ExecutorController.Executor.Status.Accepted")
-                REJECTED -> I18N.messages.getString("ExecutorController.Executor.Status.Rejected")
-                FROZEN -> I18N.messages.getString("ExecutorController.Executor.Status.Frozen")
-                RUNNING -> I18N.messages.getString("ExecutorController.Executor.Status.Running")
+            val executorResult = createExecutorAndRun(selectedAutomaton)
+            if (executorResult != null) {
+                information(
+                    I18N.messages.getString("ExecutorController.ExecutionResult"),
+                    executorResult.executionResult,
+                    graphic = executorResult.graphic,
+                    title = I18N.messages.getString("Dialog.information"),
+                    owner = uiComponent.currentWindow
+                )
             }
-            val graphic = executor.acceptedExeStates.firstOrNull()?.let { executionLeafView(it) }
-            executor.automaton.clearExecutionStates() // faster analog of executor.stop()
-            information(
-                I18N.messages.getString("ExecutorController.ExecutionResult"),
-                executionResult,
-                graphic = graphic,
-                title = I18N.messages.getString("Dialog.information"),
-                owner = uiComponent.currentWindow
-            )
         }
     }
 
     fun step(strategy: SteppingStrategy) = debuggingExecutor?.step(strategy) ?: run {
-        debuggingExecutor = startNewExecutorOrNull()
-    }
-
-    private fun startNewExecutorOrNull(): Executor? {
-        if (selectedAutomaton.problems.isNotEmpty()) {
-            error(
-                I18N.messages.getString("ExecutorController.Error.ExecutionFailed"),
-                selectedAutomaton.problems.joinToString("\n") { it.message },
-                title = I18N.messages.getString("Dialog.error"),
-                owner = uiComponent.currentWindow
-            )
-            return null
-        }
-        return Executor(selectedAutomaton).apply { start() }
+        debuggingExecutor = getNewExecutorOrNull(selectedAutomaton)
     }
 }
diff --git a/src/main/kotlin/automaton/constructor/model/automaton/AbstractAutomaton.kt b/src/main/kotlin/automaton/constructor/model/automaton/AbstractAutomaton.kt
index 24158d3..3481f88 100644
--- a/src/main/kotlin/automaton/constructor/model/automaton/AbstractAutomaton.kt
+++ b/src/main/kotlin/automaton/constructor/model/automaton/AbstractAutomaton.kt
@@ -8,6 +8,7 @@ import automaton.constructor.model.action.transition.RemoveTransitionAction
 import automaton.constructor.model.element.*
 import automaton.constructor.model.memory.MemoryUnit
 import automaton.constructor.model.memory.MemoryUnitDescriptor
+import automaton.constructor.model.memory.tape.MultiTrackTapeDescriptor
 import automaton.constructor.model.module.AutomatonModule
 import automaton.constructor.model.property.EPSILON_VALUE
 import automaton.constructor.model.transformation.AutomatonTransformation
@@ -240,6 +241,20 @@ abstract class AbstractAutomaton(
 
     private val modules = mutableMapOf<(Automaton) -> AutomatonModule, AutomatonModule>()
 
+    override fun canUseTheseDescriptors(newDescriptors: List<MemoryUnitDescriptor>): Boolean {
+        if (newDescriptors.size != memoryDescriptors.size) {
+            return false
+        }
+        for (index in memoryDescriptors.indices) {
+            if (memoryDescriptors[index]::class != newDescriptors[index]::class ||
+                memoryDescriptors[index] is MultiTrackTapeDescriptor &&
+                (memoryDescriptors[index] as MultiTrackTapeDescriptor).trackCount !=
+                (newDescriptors[index] as MultiTrackTapeDescriptor).trackCount) {
+                return false
+            }
+        }
+        return true
+    }
 
     companion object {
         private const val STATE_NAME_PREFIX = "S"
diff --git a/src/main/kotlin/automaton/constructor/model/automaton/Automaton.kt b/src/main/kotlin/automaton/constructor/model/automaton/Automaton.kt
index 1c7ff7f..411f22c 100644
--- a/src/main/kotlin/automaton/constructor/model/automaton/Automaton.kt
+++ b/src/main/kotlin/automaton/constructor/model/automaton/Automaton.kt
@@ -143,6 +143,8 @@ interface Automaton {
      * it's not invoked again and cached result of the previous invocation is returned
      */
     fun <T : AutomatonModule> getModule(moduleFactory: (Automaton) -> T): T
+
+    fun canUseTheseDescriptors(newDescriptors: List<MemoryUnitDescriptor>): Boolean
 }
 
 // Get automaton characteristics
diff --git a/src/main/kotlin/automaton/constructor/model/automaton/FiniteAutomaton.kt b/src/main/kotlin/automaton/constructor/model/automaton/FiniteAutomaton.kt
index 4982c2b..524756a 100644
--- a/src/main/kotlin/automaton/constructor/model/automaton/FiniteAutomaton.kt
+++ b/src/main/kotlin/automaton/constructor/model/automaton/FiniteAutomaton.kt
@@ -5,6 +5,7 @@ import automaton.constructor.model.action.transition.SimplifyRegexEntirelyTransi
 import automaton.constructor.model.action.transition.SimplifyRegexTransitionAction
 import automaton.constructor.model.automaton.flavours.AutomatonWithInputTape
 import automaton.constructor.model.data.FiniteAutomatonData
+import automaton.constructor.model.memory.MemoryUnitDescriptor
 import automaton.constructor.model.memory.tape.InputTapeDescriptor
 import automaton.constructor.model.transformation.DeterminizeAutomatonAction
 import automaton.constructor.utils.I18N
diff --git a/src/main/kotlin/automaton/constructor/model/automaton/MealyMooreMachine.kt b/src/main/kotlin/automaton/constructor/model/automaton/MealyMooreMachine.kt
index 1507bb1..75016d7 100644
--- a/src/main/kotlin/automaton/constructor/model/automaton/MealyMooreMachine.kt
+++ b/src/main/kotlin/automaton/constructor/model/automaton/MealyMooreMachine.kt
@@ -6,6 +6,7 @@ import automaton.constructor.model.action.state.MooreToMealyAction
 import automaton.constructor.model.automaton.flavours.AutomatonWithInputTape
 import automaton.constructor.model.automaton.flavours.AutomatonWithOutputTape
 import automaton.constructor.model.data.MealyMooreMachineData
+import automaton.constructor.model.memory.MemoryUnitDescriptor
 import automaton.constructor.model.memory.tape.InputTapeDescriptor
 import automaton.constructor.model.memory.tape.OutputTapeDescriptor
 import automaton.constructor.model.transformation.StatewiseTransformationAction
diff --git a/src/main/kotlin/automaton/constructor/model/automaton/MultiTapeTuringMachine.kt b/src/main/kotlin/automaton/constructor/model/automaton/MultiTapeTuringMachine.kt
index 4075156..becb8c9 100644
--- a/src/main/kotlin/automaton/constructor/model/automaton/MultiTapeTuringMachine.kt
+++ b/src/main/kotlin/automaton/constructor/model/automaton/MultiTapeTuringMachine.kt
@@ -2,6 +2,7 @@ package automaton.constructor.model.automaton
 
 import automaton.constructor.model.automaton.flavours.AutomatonWithTapes
 import automaton.constructor.model.data.MultiTapeTuringMachineData
+import automaton.constructor.model.memory.MemoryUnitDescriptor
 import automaton.constructor.model.memory.tape.MultiTrackTapeDescriptor
 import automaton.constructor.utils.I18N
 
diff --git a/src/main/kotlin/automaton/constructor/model/automaton/MultiTrackTuringMachine.kt b/src/main/kotlin/automaton/constructor/model/automaton/MultiTrackTuringMachine.kt
index de2e775..f931763 100644
--- a/src/main/kotlin/automaton/constructor/model/automaton/MultiTrackTuringMachine.kt
+++ b/src/main/kotlin/automaton/constructor/model/automaton/MultiTrackTuringMachine.kt
@@ -2,6 +2,7 @@ package automaton.constructor.model.automaton
 
 import automaton.constructor.model.automaton.flavours.AutomatonWithTracks
 import automaton.constructor.model.data.MultiTrackTuringMachineData
+import automaton.constructor.model.memory.MemoryUnitDescriptor
 import automaton.constructor.model.memory.tape.MultiTrackTapeDescriptor
 import automaton.constructor.utils.I18N
 
diff --git a/src/main/kotlin/automaton/constructor/model/automaton/PushdownAutomaton.kt b/src/main/kotlin/automaton/constructor/model/automaton/PushdownAutomaton.kt
index 27976c0..ab29441 100644
--- a/src/main/kotlin/automaton/constructor/model/automaton/PushdownAutomaton.kt
+++ b/src/main/kotlin/automaton/constructor/model/automaton/PushdownAutomaton.kt
@@ -4,6 +4,7 @@ import automaton.constructor.model.action.transition.EliminateEpsilonTransitionA
 import automaton.constructor.model.automaton.flavours.AutomatonWithInputTape
 import automaton.constructor.model.automaton.flavours.AutomatonWithStacks
 import automaton.constructor.model.data.PushdownAutomatonData
+import automaton.constructor.model.memory.MemoryUnitDescriptor
 import automaton.constructor.model.memory.StackDescriptor
 import automaton.constructor.model.memory.tape.InputTapeDescriptor
 import automaton.constructor.utils.I18N
diff --git a/src/main/kotlin/automaton/constructor/model/memory/Test.kt b/src/main/kotlin/automaton/constructor/model/memory/Test.kt
new file mode 100644
index 0000000..be7ad5b
--- /dev/null
+++ b/src/main/kotlin/automaton/constructor/model/memory/Test.kt
@@ -0,0 +1,9 @@
+package automaton.constructor.model.memory
+
+import automaton.constructor.model.data.MemoryUnitDescriptorData
+import kotlinx.serialization.Serializable
+
+data class Test(val input: List<MemoryUnitDescriptor>)
+
+@Serializable
+data class TestsForSerializing(val tests: List<List<MemoryUnitDescriptorData>>, val automatonType: String)
diff --git a/src/main/kotlin/automaton/constructor/model/memory/tape/MultitrackTape.kt b/src/main/kotlin/automaton/constructor/model/memory/tape/MultitrackTape.kt
index 6a883cf..a7869db 100644
--- a/src/main/kotlin/automaton/constructor/model/memory/tape/MultitrackTape.kt
+++ b/src/main/kotlin/automaton/constructor/model/memory/tape/MultitrackTape.kt
@@ -16,8 +16,8 @@ import java.text.MessageFormat
 
 class MultiTrackTapeDescriptor(val trackCount: Int) : MemoryUnitDescriptor {
     val valueProperties = List(trackCount) { "".toProperty() }
-    constructor(trackCount: Int, initValues: List<String>) : this(trackCount) {
-        valueProperties.zip(initValues).forEach { (a, b) -> a.value = b }
+    constructor(newTrackCount: Int, initialValues: List<String>) : this(newTrackCount) {
+        valueProperties.zip(initialValues).forEach { (a, b) -> a.value = b }
     }
 
     val headMoveDirection =
diff --git a/src/main/kotlin/automaton/constructor/utils/ExecutorUtils.kt b/src/main/kotlin/automaton/constructor/utils/ExecutorUtils.kt
new file mode 100644
index 0000000..d43bf09
--- /dev/null
+++ b/src/main/kotlin/automaton/constructor/utils/ExecutorUtils.kt
@@ -0,0 +1,47 @@
+package automaton.constructor.utils
+
+import automaton.constructor.model.automaton.Automaton
+import automaton.constructor.model.memory.MemoryUnit
+import automaton.constructor.model.module.executor.ExecutionStatus
+import automaton.constructor.model.module.executor.Executor
+import automaton.constructor.model.module.problems
+import automaton.constructor.view.module.executor.executionLeafView
+
+data class ExecutorResult(
+    val executionResult: String,
+    val graphic: SettingGroupEditor?
+)
+
+fun getNewExecutorOrNull(automaton: Automaton): Executor? {
+    if (automaton.problems.isNotEmpty()) {
+        tornadofx.error(
+            I18N.messages.getString("ExecutorController.Error.ExecutionFailed"),
+            automaton.problems.joinToString("\n") { it.message },
+            title = I18N.messages.getString("Dialog.error")
+        )
+        return null
+    }
+    return Executor(automaton)
+}
+
+fun createExecutorAndRun(automaton: Automaton, memory: List<MemoryUnit>? = null): ExecutorResult? {
+    val executor = getNewExecutorOrNull(automaton)
+    if (executor == null) {
+        return null
+    }
+    if (memory == null) {
+        executor.start()
+    } else {
+        executor.start(memory)
+    }
+    executor.runFor()
+    val executionResult = when (executor.status) {
+        ExecutionStatus.ACCEPTED -> I18N.messages.getString("ExecutorController.Executor.Status.Accepted")
+        ExecutionStatus.REJECTED -> I18N.messages.getString("ExecutorController.Executor.Status.Rejected")
+        ExecutionStatus.FROZEN -> I18N.messages.getString("ExecutorController.Executor.Status.Frozen")
+        ExecutionStatus.RUNNING -> I18N.messages.getString("ExecutorController.Executor.Status.Running")
+    }
+    val graphic = executor.acceptedExeStates.firstOrNull()?.let { executionLeafView(it) }
+    automaton.clearExecutionStates()
+    return ExecutorResult(executionResult, graphic)
+}
diff --git a/src/main/kotlin/automaton/constructor/view/ExamplesView.kt b/src/main/kotlin/automaton/constructor/view/ExamplesView.kt
index a73ea39..f9a454c 100644
--- a/src/main/kotlin/automaton/constructor/view/ExamplesView.kt
+++ b/src/main/kotlin/automaton/constructor/view/ExamplesView.kt
@@ -19,10 +19,7 @@ import kotlin.io.path.Path
 @Serializable
 data class Example(val name: String, val description: String)
 
-class ExampleCell(
-    private val counter: IntegerProperty,
-    private val automatonName: StringProperty
-): ListCell<Example?>() {
+class ExampleCell(private val automatonName: StringProperty): ListCell<Example?>() {
     init {
         this.setOnMouseClicked {
             if (it.clickCount == 2 && this.item != null)
@@ -32,7 +29,6 @@ class ExampleCell(
     override fun updateItem(item: Example?, empty: Boolean) {
         super.updateItem(item, empty)
         graphic = if (item != null) {
-            counter.set(counter.value + 1) // this whole counter thing obviously needs to be remade
             Text().apply { text = I18N.automatonExamples.getString("ExamplesFragment.${item.name}") }
         } else
             null
@@ -52,22 +48,20 @@ class ExamplesView: View() {
         val description = Text().apply { text = I18N.messages.getString("ExamplesFragment.Choose") }
         val image = ImageView()
         val descriptionVBox = VBox(description, image)
-        val counter = 0.toProperty()
         val automatonName = "".toProperty()
         minWidth = 800.0
+
         add(descriptionVBox)
-        examplesListView.setCellFactory { ExampleCell(counter, automatonName) }
-        counter.addListener(ChangeListener { _, _, _ ->
-            val selectedCellIndex = examplesListView.selectionModel.selectedIndex
-            if (selectedCellIndex != -1) {
-                description.text =
-                    I18N.automatonExamples.getString(
-                        "ExamplesFragment.${examples[selectedCellIndex].name}Description")
-                image.image = Image(
-                    "file:///${System.getProperty("user.dir")}/src/main/resources/examples/images/${examples[selectedCellIndex].name}.png",
-                    true)
-            }
+
+        examplesListView.setCellFactory { ExampleCell(automatonName) }
+
+        examplesListView.selectionModel.selectedItemProperty().addListener(ChangeListener { _, _, newValue ->
+            description.text = I18N.automatonExamples.getString("ExamplesFragment.${newValue.name}Description")
+            image.image = Image(
+                "file:///${System.getProperty("user.dir")}/src/main/resources/examples/images/${newValue.name}.png",
+                true)
         })
+
         automatonName.addListener(ChangeListener { _, _, newValue ->
             val automatonsPath = Path("${System.getProperty("user.dir")}/src/main/resources/examples/automatons")
             Files.walk(automatonsPath).forEach {
diff --git a/src/main/kotlin/automaton/constructor/view/TestsResultsFragment.kt b/src/main/kotlin/automaton/constructor/view/TestsResultsFragment.kt
index 35cba7a..742bcd5 100644
--- a/src/main/kotlin/automaton/constructor/view/TestsResultsFragment.kt
+++ b/src/main/kotlin/automaton/constructor/view/TestsResultsFragment.kt
@@ -1,6 +1,6 @@
 package automaton.constructor.view
 
-import automaton.constructor.controller.Test
+import automaton.constructor.model.memory.Test
 import automaton.constructor.utils.I18N
 import automaton.constructor.utils.SettingGroup
 import automaton.constructor.utils.SettingGroupEditor
diff --git a/src/main/kotlin/automaton/constructor/view/TestsView.kt b/src/main/kotlin/automaton/constructor/view/TestsView.kt
index 82b9ee5..50a3ea6 100644
--- a/src/main/kotlin/automaton/constructor/view/TestsView.kt
+++ b/src/main/kotlin/automaton/constructor/view/TestsView.kt
@@ -1,7 +1,7 @@
 package automaton.constructor.view
 
-import automaton.constructor.controller.Test
 import automaton.constructor.controller.TestsController
+import automaton.constructor.model.memory.Test
 import automaton.constructor.utils.*
 import tornadofx.*
 import javafx.scene.control.Button
@@ -33,6 +33,7 @@ class TestCell(val controller: TestsController): ListCell<Test>() {
 class TestsView: View() {
     val controller: TestsController by param()
     private val tests = mutableListOf<Test>().asObservable()
+
     override fun onDock() {
         currentWindow?.setOnCloseRequest {
             if (!controller.suggestSavingChanges(tests, this))
@@ -41,12 +42,14 @@ class TestsView: View() {
                 tests.clear()
         }
     }
+
     override val root = vbox {
         val addButton = Button(I18N.messages.getString("TestsFragment.Add"))
         val deleteButton = Button(I18N.messages.getString("TestsFragment.Delete"))
         val saveButton = Button(I18N.messages.getString("TestsFragment.Save"))
         val loadButton = Button(I18N.messages.getString("TestsFragment.Load"))
         minWidth = 500.0 // just for testing
+
         hbox {
             add(addButton)
             add(deleteButton)
@@ -61,18 +64,22 @@ class TestsView: View() {
         }
 
         testsListView.setCellFactory { TestCell(controller) }
+
         addButton.setOnAction {
             tests.add(Test(controller.openedAutomaton.memoryDescriptors.map { it.copy() }))
         }
+
         deleteButton.setOnAction {
             val selectedCellIndex = testsListView.selectionModel.selectedIndex
             if (selectedCellIndex != -1) {
                 tests.removeAt(selectedCellIndex)
             }
         }
+
         saveButton.setOnAction {
             controller.saveTests(tests, this@TestsView)
         }
+
         loadButton.setOnAction {
             val openedTests = controller.openTests(this@TestsView)
             openedTests.forEach { test -> tests.add(test) }
diff --git a/src/main/resources/examples/automatons/correctBracketSeqRecognizer.atmtn b/src/main/resources/examples/automatons/correctBracketSeqRecognizer.atmtn
index 5c93c2f..dc111de 100644
--- a/src/main/resources/examples/automatons/correctBracketSeqRecognizer.atmtn
+++ b/src/main/resources/examples/automatons/correctBracketSeqRecognizer.atmtn
@@ -10,73 +10,34 @@
         ]
     },
     "vertices": [
-        {
-            "type": "state",
-            "id": 5,
-            "name": "S5",
-            "x": 497707.5165449231,
-            "y": 500085.0165449231,
-            "isFinal": true
-        },
-        {
-            "type": "state",
-            "id": 0,
-            "name": "S0",
-            "x": 498787.5,
-            "y": 500075.0,
-            "isInitial": true
-        },
-        {
-            "type": "state",
-            "id": 3,
-            "name": "S3",
-            "x": 499860.0165449231,
-            "y": 500712.5165449231
-        },
         {
             "type": "state",
             "id": 1,
             "name": "S1",
-            "x": 499857.5165449231,
-            "y": 499382.5165449231
-        },
-        {
-            "type": "state",
-            "id": 6,
-            "name": "S6",
-            "x": 497705.0165449231,
-            "y": 500720.0165449231,
-            "isFinal": true
+            "x": 499154.9762463273,
+            "y": 500132.4762463273
         },
         {
             "type": "state",
-            "id": 4,
-            "name": "S4",
-            "x": 497712.5165449231,
-            "y": 499375.0165449231,
+            "id": 2,
+            "name": "S2",
+            "x": 499837.47535379225,
+            "y": 500127.47535379225,
             "isFinal": true
         },
         {
             "type": "state",
-            "id": 2,
-            "name": "S2",
-            "x": 499855.0165449231,
-            "y": 500057.5165449231
+            "id": 0,
+            "name": "S0",
+            "x": 498464.990869239,
+            "y": 500139.990869239,
+            "isInitial": true
         }
     ],
     "transitions": [
         {
-            "source": 6,
-            "target": 0,
-            "properties": [
-                "ε",
-                "ε",
-                "ε"
-            ]
-        },
-        {
-            "source": 0,
-            "target": 3,
+            "source": 1,
+            "target": 1,
             "properties": [
                 "[",
                 "ε",
@@ -84,94 +45,67 @@
             ]
         },
         {
-            "source": 0,
-            "target": 2,
-            "properties": [
-                "{",
-                "ε",
-                "{"
-            ]
-        },
-        {
-            "source": 3,
-            "target": 0,
+            "source": 1,
+            "target": 1,
             "properties": [
-                "ε",
-                "ε",
+                ")",
+                "(",
                 "ε"
             ]
         },
         {
-            "source": 0,
-            "target": 5,
+            "source": 1,
+            "target": 1,
             "properties": [
-                "}",
-                "{",
+                "]",
+                "[",
                 "ε"
             ]
         },
         {
-            "source": 5,
-            "target": 0,
+            "source": 1,
+            "target": 1,
             "properties": [
+                "{",
                 "ε",
-                "ε",
-                "ε"
+                "{"
             ]
         },
         {
             "source": 1,
-            "target": 0,
+            "target": 2,
             "properties": [
                 "ε",
-                "ε",
+                "$",
                 "ε"
             ]
         },
         {
-            "source": 4,
-            "target": 0,
+            "source": 0,
+            "target": 1,
             "properties": [
                 "ε",
                 "ε",
-                "ε"
+                "$"
             ]
         },
         {
-            "source": 0,
-            "target": 6,
-            "properties": [
-                "]",
-                "[",
-                "ε"
-            ]
-        },
-        {
-            "source": 0,
-            "target": 4,
+            "source": 1,
+            "target": 1,
             "properties": [
-                ")",
-                "(",
+                "}",
+                "{",
                 "ε"
             ]
         },
         {
-            "source": 0,
+            "source": 1,
             "target": 1,
             "properties": [
                 "(",
                 "ε",
                 "("
             ]
-        },
-        {
-            "source": 2,
-            "target": 0,
-            "properties": [
-                "ε",
-                "ε",
-                "ε"
-            ]
         }
     ]
 }
\ No newline at end of file
diff --git a/src/main/resources/examples/images/binaryNumberAdder.png b/src/main/resources/examples/images/binaryNumberAdder.png
index 9eebf8e..238a5c5 100644
Binary files a/src/main/resources/examples/images/binaryNumberAdder.png and b/src/main/resources/examples/images/binaryNumberAdder.png differ
diff --git a/src/main/resources/examples/images/correctBracketSeqRecognizer.png b/src/main/resources/examples/images/correctBracketSeqRecognizer.png
index 974d832..dad8451 100644
Binary files a/src/main/resources/examples/images/correctBracketSeqRecognizer.png and b/src/main/resources/examples/images/correctBracketSeqRecognizer.png differ
diff --git a/src/main/resources/examples/images/evenBinaryNumbersRecognizer.png b/src/main/resources/examples/images/evenBinaryNumbersRecognizer.png
index a3e3e98..6d934ab 100644
Binary files a/src/main/resources/examples/images/evenBinaryNumbersRecognizer.png and b/src/main/resources/examples/images/evenBinaryNumbersRecognizer.png differ
diff --git a/src/main/resources/examples/images/evenPalindromesRecognizer.png b/src/main/resources/examples/images/evenPalindromesRecognizer.png
index 79c64ee..aaf2056 100644
Binary files a/src/main/resources/examples/images/evenPalindromesRecognizer.png and b/src/main/resources/examples/images/evenPalindromesRecognizer.png differ
diff --git a/src/main/resources/examples/images/threeZerosAndOneOne.png b/src/main/resources/examples/images/threeZerosAndOneOne.png
index a49a133..4fe3d3d 100644
Binary files a/src/main/resources/examples/images/threeZerosAndOneOne.png and b/src/main/resources/examples/images/threeZerosAndOneOne.png differ
diff --git a/src/main/resources/examples/images/zeroRemover.png b/src/main/resources/examples/images/zeroRemover.png
index 7917384..73a1cbe 100644
Binary files a/src/main/resources/examples/images/zeroRemover.png and b/src/main/resources/examples/images/zeroRemover.png differ
diff --git a/src/test/kotlin/automaton/constructor/model/TestingTests.kt b/src/test/kotlin/automaton/constructor/model/TestingTests.kt
index 9e986c1..a430f1c 100644
--- a/src/test/kotlin/automaton/constructor/model/TestingTests.kt
+++ b/src/test/kotlin/automaton/constructor/model/TestingTests.kt
@@ -2,19 +2,17 @@ package automaton.constructor.model
 
 import automaton.constructor.AutomatonConstructorApp
 import automaton.constructor.utils.I18N
-import automaton.constructor.view.MainWindow
 import javafx.application.Application
 import javafx.scene.Node
 import javafx.stage.Stage
 import org.junit.jupiter.api.AfterEach
+import org.junit.jupiter.api.Assumptions.assumeFalse
 import org.junit.jupiter.api.BeforeEach
 import org.junit.jupiter.api.Test
 import org.testfx.api.FxAssert.verifyThat
 import org.testfx.api.FxToolkit
 import org.testfx.framework.junit5.ApplicationTest
 import org.testfx.matcher.control.TableViewMatchers.hasTableCell
-import tornadofx.*
-
 
 class TestingTests: ApplicationTest() {
     private lateinit var app: Application
@@ -46,6 +44,10 @@ class TestingTests: ApplicationTest() {
 
     @Test
     fun runningTestOnFiniteAutomatonTest() {
+        assumeFalse(
+            System.getProperty("testfx.headless") == "true",
+            "Tests requiring graphical UI will be skipped in headless mode"
+        )
         openExampleAndRunTest(I18N.automatonExamples.getString(
             "ExamplesFragment.evenBinaryNumbersRecognizer"), "1")
         verifyThat(".table-view", hasTableCell(I18N.messages.getString(
@@ -54,6 +56,10 @@ class TestingTests: ApplicationTest() {
 
     @Test
     fun runningTestOnCorrectBracketSequenceRecognizer() {
+        assumeFalse(
+            System.getProperty("testfx.headless") == "true",
+            "Tests requiring graphical UI will be skipped in headless mode"
+        )
         openExampleAndRunTest(I18N.automatonExamples.getString(
             "ExamplesFragment.correctBracketSeqRecognizer"), "()[]{}")
         verifyThat(".table-view", hasTableCell(I18N.messages.getString(
@@ -62,6 +68,10 @@ class TestingTests: ApplicationTest() {
 
     @Test
     fun runningTestOnTuringMachine() {
+        assumeFalse(
+            System.getProperty("testfx.headless") == "true",
+            "Tests requiring graphical UI will be skipped in headless mode"
+        )
         openExampleAndRunTest(I18N.automatonExamples.getString(
             "ExamplesFragment.binaryNumberAdder"), "100+111")
         verifyThat(".table-view", hasTableCell(I18N.messages.getString(
@@ -70,6 +80,10 @@ class TestingTests: ApplicationTest() {
 
     @Test
     fun runningTestOnEvenPalindromesRecognizer() {
+        assumeFalse(
+            System.getProperty("testfx.headless") == "true",
+            "Tests requiring graphical UI will be skipped in headless mode"
+        )
         openExampleAndRunTest(I18N.automatonExamples.getString(
             "ExamplesFragment.evenPalindromesRecognizer"), "110011")
         verifyThat(".table-view", hasTableCell(I18N.messages.getString(
@@ -78,6 +92,10 @@ class TestingTests: ApplicationTest() {
 
     @Test
     fun runningTestOnRegisterAutomaton() {
+        assumeFalse(
+            System.getProperty("testfx.headless") == "true",
+            "Tests requiring graphical UI will be skipped in headless mode"
+        )
         openExampleAndRunTest(I18N.automatonExamples.getString(
             "ExamplesFragment.threeZerosAndOneOne"), "110011")
         verifyThat(".table-view", hasTableCell(I18N.messages.getString(
@@ -86,6 +104,10 @@ class TestingTests: ApplicationTest() {
 
     @Test
     fun runningTestOnMealyMooreMachine() {
+        assumeFalse(
+            System.getProperty("testfx.headless") == "true",
+            "Tests requiring graphical UI will be skipped in headless mode"
+        )
         openExampleAndRunTest(I18N.automatonExamples.getString(
             "ExamplesFragment.zeroRemover"), "110011")
         verifyThat(".table-view", hasTableCell(I18N.messages.getString(
diff --git a/src/test/kotlin/automaton/constructor/model/module/executor/ExecutorTest.kt b/src/test/kotlin/automaton/constructor/model/module/executor/ExecutorTest.kt
index d98bc23..af9d4a0 100644
--- a/src/test/kotlin/automaton/constructor/model/module/executor/ExecutorTest.kt
+++ b/src/test/kotlin/automaton/constructor/model/module/executor/ExecutorTest.kt
@@ -18,7 +18,7 @@ import kotlin.test.assertEquals
 
 class ExecutorTest {
     companion object {
-        const val MAX_RUN_MILLIS = 100L
+        const val MAX_RUN_MILLIS = 200L
     }
 
     @Nested