diff --git a/README.md b/README.md
index 7228ebc..740bec9 100644
--- a/README.md
+++ b/README.md
@@ -200,9 +200,9 @@ ExecutionEnv env = new ExecutionEnv();
 env.insertFunction("input", in::nextDouble);
 
 env.insertFunction("isleapyear", 1, ctx -> {
-    // need a FunctionContext param in order to get an int
-    int year = ctx.getInt(0); 
-    // copied from java.time.Year.isLeap
+    // you need a FunctionContext parameter to force the input to be an int
+    // as all parameters are doubles implicitly  
+    int year = ctx.getInt(0);
     return Utility.boolToDouble(java.time.Year.isLeap(year));
 });
 
diff --git a/core/src/main/java/me/fourteendoggo/mathexpressionparser/ExpressionParser.java b/core/src/main/java/me/fourteendoggo/mathexpressionparser/ExpressionParser.java
index 9de04b6..34c6f9e 100644
--- a/core/src/main/java/me/fourteendoggo/mathexpressionparser/ExpressionParser.java
+++ b/core/src/main/java/me/fourteendoggo/mathexpressionparser/ExpressionParser.java
@@ -15,11 +15,15 @@
 import java.util.function.DoubleUnaryOperator;
 import java.util.function.ToDoubleFunction;
 
+@SuppressWarnings("unused")
 public class ExpressionParser {
     private static ExecutionEnv DEFAULT_ENV;
 
     private ExpressionParser() {}
 
+    /**
+     * @see ExpressionParser#parse(String, ExecutionEnv)
+     */
     public static double parse(String input) {
         return parse(input, getDefaultEnv());
     }
@@ -89,7 +93,7 @@ public static void insertSymbol(Symbol symbol) {
         getDefaultEnv().insertSymbol(symbol);
     }
 
-    public static ExecutionEnv getDefaultEnv() {
+    private static ExecutionEnv getDefaultEnv() {
         if (DEFAULT_ENV == null) {
             DEFAULT_ENV = new ExecutionEnv();
         }