diff --git a/src/main/java/org/cbioportal/service/util/SessionServiceRequestHandler.java b/src/main/java/org/cbioportal/service/util/SessionServiceRequestHandler.java
index 48322e367bd..f943eb93e19 100644
--- a/src/main/java/org/cbioportal/service/util/SessionServiceRequestHandler.java
+++ b/src/main/java/org/cbioportal/service/util/SessionServiceRequestHandler.java
@@ -10,7 +10,6 @@
 import com.mongodb.BasicDBObject;
 import org.apache.commons.codec.binary.Base64;
 import org.apache.commons.lang3.StringUtils;
-import org.cbioportal.web.PublicVirtualStudiesController;
 import org.cbioportal.web.parameter.VirtualStudy;
 import org.cbioportal.web.parameter.VirtualStudyData;
 import org.slf4j.Logger;
diff --git a/src/main/java/org/cbioportal/web/PublicVirtualStudiesController.java b/src/main/java/org/cbioportal/web/PublicVirtualStudiesController.java
index b39f3d8cffc..d7360a1165e 100644
--- a/src/main/java/org/cbioportal/web/PublicVirtualStudiesController.java
+++ b/src/main/java/org/cbioportal/web/PublicVirtualStudiesController.java
@@ -107,7 +107,7 @@ public ResponseEntity<VirtualStudy> publishVirtualStudy(
 
     @DeleteMapping("/{id}")
     @ApiResponse(responseCode = "200", description = "OK")
-    public ResponseEntity retractVirtualStudy(
+    public ResponseEntity<?> retractVirtualStudy(
         @PathVariable String id,
         @RequestHeader(value = "X-PUBLISHER-API-KEY") String providedPublisherApiKey
     ) {
diff --git a/src/test/java/org/cbioportal/test/integration/PublicVirtualStudiesIntegrationTest.java b/src/test/java/org/cbioportal/test/integration/PublicVirtualStudiesIntegrationTest.java
index 982fa29c964..ab831592bba 100644
--- a/src/test/java/org/cbioportal/test/integration/PublicVirtualStudiesIntegrationTest.java
+++ b/src/test/java/org/cbioportal/test/integration/PublicVirtualStudiesIntegrationTest.java
@@ -53,33 +53,33 @@
 @FixMethodOrder(MethodSorters.NAME_ASCENDING)
 public class PublicVirtualStudiesIntegrationTest extends ContainerConfig {
 
-    final static String CBIO_URL = String.format("http://localhost:%d", CBIO_PORT);
+    static final String CBIO_URL = String.format("http://localhost:%d", CBIO_PORT);
 
-    final static HttpHeaders jsonContentType = new HttpHeaders() {
+    static final HttpHeaders jsonContentType = new HttpHeaders() {
         {
             set("Content-Type", "application/json");
         }
     };
-    
-    final static HttpHeaders invalidKeyContainingHeaders = new HttpHeaders() {
+
+    static final HttpHeaders invalidKeyContainingHeaders = new HttpHeaders() {
         {
             set("X-PUBLISHER-API-KEY", "this-is-not-valid-key");
         }
     };
-    
-    final static HttpHeaders validKeyContainingHeaders = new HttpHeaders() {
+
+    static final HttpHeaders validKeyContainingHeaders = new HttpHeaders() {
         {
             set("X-PUBLISHER-API-KEY", "this-is-a-secret");
         }
     };
-    
-    final static ParameterizedTypeReference<List<VirtualStudy>> typeRef = new ParameterizedTypeReference<>() {
+
+    static final ParameterizedTypeReference<List<VirtualStudy>> typeRef = new ParameterizedTypeReference<>() {
     };
 
     static String createdVsId;
     static String publishedVsId;
 
-    final static VirtualStudyData virtualStudyDataToSave = createTestVsData();
+    static final VirtualStudyData virtualStudyDataToSave = createTestVsData();
 
     @Autowired
     private TestRestTemplate restTemplate;
@@ -93,7 +93,7 @@ public void test1NoPublicVirtualStudiesAtTheBeginning() {
             typeRef);
 
         assertThat(response1.getStatusCode().is2xxSuccessful()).isTrue();
-        assertThat(response1.getBody()).hasSize(0);
+        assertThat(response1.getBody()).isEmpty();
     }
     
     @Test
@@ -193,7 +193,7 @@ public void test6NoPublicVirtualStudiesAfterRemoval() {
             typeRef);
 
         assertThat(response6.getStatusCode().is2xxSuccessful()).isTrue();
-        assertThat(response6.getBody()).hasSize(0);
+        assertThat(response6.getBody()).isEmpty();
     }
 
     static VirtualStudyData createTestVsData() {