Java 11 migrate remaining p (#1122)

* Moves partial-response to Java 11

* Moves pipeline to Java 11

* Moves poison-pill to Java 11

* Moves priority-queue to Java 11

* Moves private-class-data to Java 11

* Moves producer-consumer to Java 11

* Moves promise to Java 11

* Moves property to Java 11

* Moves prototype to Java 11

* Moves proxy to Java 11

* Corrects checkstyle errors

* Fixes build for pipeline pattern

private-class-data/src/test/java/com/iluwatar/privateclassdata/AppTest.java

@@ -26,15 +26,12 @@ package com.iluwatar.privateclassdata;
 import org.junit.jupiter.api.Test;
 
 /**
- * 
  * Application test
- *
  */
 public class AppTest {
 
   @Test
   public void test() {
-    String[] args = {};
-    App.main(args);
+    App.main(new String[]{});
   }
 }