docs: double dispatch explanation + refactor (#2915)

double-dispatch/src/main/java/com/iluwatar/doubledispatch/GameObject.java

@@ -24,9 +24,14 @@
  */
 package com.iluwatar.doubledispatch;
 
+import lombok.Getter;
+import lombok.Setter;
+
 /**
  * Game objects have coordinates and some other status information.
  */
+@Getter
+@Setter
 public abstract class GameObject extends Rectangle {
 
   private boolean damaged;
@@ -42,22 +47,6 @@ public abstract class GameObject extends Rectangle {
         super.toString(), isDamaged(), isOnFire());
   }
 
-  public boolean isOnFire() {
-    return onFire;
-  }
-
-  public void setOnFire(boolean onFire) {
-    this.onFire = onFire;
-  }
-
-  public boolean isDamaged() {
-    return damaged;
-  }
-
-  public void setDamaged(boolean damaged) {
-    this.damaged = damaged;
-  }
-
   public abstract void collision(GameObject gameObject);
 
   public abstract void collisionResolve(FlamingAsteroid asteroid);

double-dispatch/src/test/java/com/iluwatar/doubledispatch/AppTest.java

@@ -35,7 +35,6 @@ class AppTest {
 
   /**
    * Issue: Add at least one assertion to this test case.
-   *
    * Solution: Inserted assertion to check whether the execution of the main method in {@link App#main(String[])}
    * throws an exception.
    */

double-dispatch/src/test/java/com/iluwatar/doubledispatch/RectangleTest.java

@@ -52,7 +52,7 @@ class RectangleTest {
    * #toString()}
    */
   @Test
-  void testToString() throws Exception {
+  void testToString() {
     final var rectangle = new Rectangle(1, 2, 3, 4);
     assertEquals("[1,2,3,4]", rectangle.toString());
   }