Java 11 migrate c-d (remaining) (#1111)

* Moves converter pattern to Java 11

* Moves cqrs pattern to Java 11

* Moves dao pattern to Java 11

* Moves data-bus pattern to Java 11

* Moves data-locality pattern to Java 11

* Moves data-mapper pattern to Java 11

* Moves data-transfer-object pattern to Java 11

* Moves decorator pattern to Java 11

* Moves delegation pattern to Java 11

* Moves dependency-injection to Java 11

* Moves dirty-flag to Java 11

* Moves double-buffer to Java 11

* Moves double-checked-locking to Java 11

* Moves double-dispatch to Java 11

* Corrects with changes thats breaking test cases

dirty-flag/src/test/java/org/dirty/flag/AppTest.java

@@ -23,19 +23,15 @@
 
 package org.dirty.flag;
 
-import java.io.IOException;
-
-import org.junit.jupiter.api.Test;
-
 import com.iluwatar.dirtyflag.App;
+import org.junit.jupiter.api.Test;
 
 /**
  * Tests that Dirty-Flag example runs without errors.
  */
 public class AppTest {
   @Test
-  public void test() throws IOException {
-    String[] args = {};
-    App.main(args);
+  public void test() {
+    App.main(new String[]{});
   }
 }

dirty-flag/src/test/java/org/dirty/flag/DirtyFlagTest.java

@@ -26,31 +26,26 @@ package org.dirty.flag;
 import static org.junit.jupiter.api.Assertions.assertFalse;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 
-import java.util.List;
-
+import com.iluwatar.dirtyflag.DataFetcher;
 import org.junit.jupiter.api.Test;
 
-import com.iluwatar.dirtyflag.DataFetcher;
-
 /**
- *
  * Application test
- *
  */
 public class DirtyFlagTest {
 
   @Test
   public void testIsDirty() {
-    DataFetcher df = new DataFetcher();
-    List<String> countries = df.fetch();
+    var df = new DataFetcher();
+    var countries = df.fetch();
     assertFalse(countries.isEmpty());
   }
 
   @Test
   public void testIsNotDirty() {
-    DataFetcher df = new DataFetcher();
+    var df = new DataFetcher();
     df.fetch();
-    List<String> countries = df.fetch();
+    var countries = df.fetch();
     assertTrue(countries.isEmpty());
   }
 }