dependencies: #2449 bump maven-checkstyle-plugin from 3.1.0 to 3.2.0 + resolve chec… (#2464)

* #2449 bump maven-checkstyle-plugin from 3.1.0 to 3.2.0 + resolve checkstyle issues

* remove FileSelectorJFrame.java to resolve checkstyle issue

* remove FileSelectorJFrame.java to resolve checkstyle issue

* remove FileSelectorJFrame.java to resolve checkstyle issue

* add refactored file with correct filename to resolve checkstyle issue

* add the test data

* change filenames from JFrame to Jframe for checkstyle

* fix code smell from  sonar report

* add new testcases to improve the test coverage

* remove code smell

filterer/src/main/java/com/iluwatar/filterer/threat/ProbabilisticThreatAwareSystem.java

@@ -25,7 +25,6 @@
 package com.iluwatar.filterer.threat;
 
 import com.iluwatar.filterer.domain.Filterer;
-
 import java.util.List;
 
 /**
@@ -35,14 +34,14 @@ public interface ProbabilisticThreatAwareSystem extends ThreatAwareSystem {
 
   /**
    * {@inheritDoc}
-   * @return
+   * @return {@link ProbableThreat}
    */
   @Override
   List<? extends ProbableThreat> threats();
 
   /**
    * {@inheritDoc}
-   * @return
+   * @return {@link Filterer}
    */
   @Override
   Filterer<? extends ProbabilisticThreatAwareSystem, ? extends ProbableThreat> filtered();

filterer/src/main/java/com/iluwatar/filterer/threat/ThreatAwareSystem.java

@@ -25,7 +25,6 @@
 package com.iluwatar.filterer.threat;
 
 import com.iluwatar.filterer.domain.Filterer;
-
 import java.util.List;
 
 /**

filterer/src/main/java/com/iluwatar/filterer/threat/ThreatType.java

@@ -24,6 +24,9 @@
  */
 package com.iluwatar.filterer.threat;
 
+/**
+ * Enum class representing Threat types.
+ */
 public enum ThreatType {
   TROJAN,
   WORM,

filterer/src/test/java/com/iluwatar/filterer/threat/SimpleThreatAwareSystemTest.java

@@ -25,7 +25,6 @@
 package com.iluwatar.filterer.threat;
 
 import org.junit.jupiter.api.Test;
-
 import java.util.List;
 
 import static org.junit.jupiter.api.Assertions.*;