decrease number of checkstyle errors in singleton, strategy and visitor patterns #1021 (#1054)

* fix checkstlye errors - visitor pattern

* fix checkstlye errors - strategy pattern

* fix checkstlye errors - singleton pattern

strategy/src/test/java/com/iluwatar/strategy/AppTest.java

@@ -26,9 +26,7 @@ package com.iluwatar.strategy;
 import org.junit.jupiter.api.Test;
 
 /**
- * 
- * Application test
- *
+ * Application test.
  */
 public class AppTest {
 

strategy/src/test/java/com/iluwatar/strategy/DragonSlayerTest.java

@@ -23,21 +23,21 @@
 
 package com.iluwatar.strategy;
 
-import org.junit.jupiter.api.Test;
-
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.verifyNoMoreInteractions;
 
+import org.junit.jupiter.api.Test;
+
 /**
- * Date: 12/29/15 - 10:50 PM
+ * Date: 12/29/15 - 10:50 PM.
  *
  * @author Jeroen Meulemeester
  */
 public class DragonSlayerTest {
 
   /**
-   * Verify if the dragon slayer uses the strategy during battle
+   * Verify if the dragon slayer uses the strategy during battle.
    */
   @Test
   public void testGoToBattle() {
@@ -50,7 +50,7 @@ public class DragonSlayerTest {
   }
 
   /**
-   * Verify if the dragon slayer uses the new strategy during battle after a change of strategy
+   * Verify if the dragon slayer uses the new strategy during battle after a change of strategy.
    */
   @Test
   public void testChangeStrategy() {

strategy/src/test/java/com/iluwatar/strategy/DragonSlayingStrategyTest.java

@@ -23,45 +23,48 @@
 
 package com.iluwatar.strategy;
 
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
 import ch.qos.logback.classic.Logger;
 import ch.qos.logback.classic.spi.ILoggingEvent;
 import ch.qos.logback.core.AppenderBase;
+
+import java.util.Collection;
+import java.util.LinkedList;
+import java.util.List;
+
 import org.junit.jupiter.api.AfterEach;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.params.ParameterizedTest;
 import org.junit.jupiter.params.provider.MethodSource;
 import org.slf4j.LoggerFactory;
 
-import java.util.Collection;
-import java.util.LinkedList;
-import java.util.List;
-
-import static org.junit.jupiter.api.Assertions.assertEquals;
-
 /**
- * Date: 12/29/15 - 10:58 PM
+ * Date: 12/29/15 - 10:58 PM.
  *
  * @author Jeroen Meulemeester
  */
 public class DragonSlayingStrategyTest {
 
   /**
+   * Assembles test parameters.
+   *
    * @return The test parameters for each cycle
    */
   static Collection<Object[]> dataProvider() {
-      return List.of(
-          new Object[]{
-              new MeleeStrategy(),
-              "With your Excalibur you sever the dragon's head!"
-          },
-          new Object[]{
-              new ProjectileStrategy(),
-              "You shoot the dragon with the magical crossbow and it falls dead on the ground!"
-          },
-          new Object[]{
-              new SpellStrategy(),
-              "You cast the spell of disintegration and the dragon vaporizes in a pile of dust!"
-          }
+    return List.of(
+      new Object[]{
+        new MeleeStrategy(),
+        "With your Excalibur you sever the dragon's head!"
+      },
+      new Object[]{
+        new ProjectileStrategy(),
+        "You shoot the dragon with the magical crossbow and it falls dead on the ground!"
+      },
+      new Object[]{
+        new SpellStrategy(),
+        "You cast the spell of disintegration and the dragon vaporizes in a pile of dust!"
+      }
     );
   }
 
@@ -79,7 +82,7 @@ public class DragonSlayingStrategyTest {
 
 
   /**
-   * Test if executing the strategy gives the correct response
+   * Test if executing the strategy gives the correct response.
    */
   @ParameterizedTest
   @MethodSource("dataProvider")