title: ArrayList add method is overwriting Objects in the list
body: <p>So, when I try adding a Trick to an ArrayList the Trick that is added overwrites what is already in the ArrayList so that all the elements in the ArrayList consists of the trick I have just added.</p>
  
  <p>These methods are in my main class:</p>
  
  <pre><code>public Trick playTrick(Player firstPlayer){
       Trick t=new Trick(firstPlayer.getID());
          return t;
  
  }
  
  
  public void playGame(){
  
      for(int i=0;i&lt;NOS_TRICKS;i++){
  
          Trick t=playTrick(players[firstPlayer]);
          players[firstPlayer].update(t);
          //System.out.println(t.completedTricks);
      }
  
  }
  </code></pre>
  
  <p>The error is occurring when players[firstPlayer].update(t) is called, update(t) adds Trick t to my ArrayList:</p>
  
  <pre><code>public class BPlayer implents Player{
     public void update(Trick t){
         this.strategy.updateData(t);
     }
  }
  </code></pre>
  
  <p>This then triggers updateData:</p>
  
  <pre><code>public class AdvStrategy implements Strategy{
      public static ArrayList&lt;Trick&gt; completedTricks = new ArrayList&lt;&gt;();
  
      @Override
      public void updateData(Trick c) {
          completedTricks.add(c);
      }
  }
  </code></pre>
  
  <p>Example of my output when printing the ArrayList:</p>
  
  <pre><code>Trick ={3=KING DIAMONDS, 0=TWO DIAMONDS, 1=THREE DIAMONDS, 2=FIVE DIAMONDS}
  Lead =3 Winner =3 DIAMONDS
  ARRAYLIST[{3=KING DIAMONDS, 0=TWO DIAMONDS, 1=THREE DIAMONDS, 2=FIVE DIAMONDS}]
  Trick ={3=QUEEN DIAMONDS, 0=FOUR DIAMONDS, 1=SIX DIAMONDS, 2=TEN DIAMONDS}
  Lead =3 Winner =3 DIAMONDS
  ARRAYLIST[{3=QUEEN DIAMONDS, 0=FOUR DIAMONDS, 1=SIX DIAMONDS, 2=TEN DIAMONDS}, {3=QUEEN DIAMONDS, 0=FOUR DIAMONDS, 1=SIX DIAMONDS, 2=TEN DIAMONDS}]
  </code></pre>
  
  <p>Last line of output should be this when working...</p>
  
  <pre><code>ARRAYLIST[{3=KING DIAMONDS, 0=TWO DIAMONDS, 1=THREE DIAMONDS, 2=FIVE DIAMONDS}, {3=QUEEN DIAMONDS, 0=FOUR DIAMONDS, 1=SIX DIAMONDS, 2=TEN DIAMONDS}]
  </code></pre>