title: custom arraylist<mygames> get distinct
body: <p>is there any way to get the distinct values of a custom arraylist?</p>
  
  <pre><code>public class mystatistic extends BaseActivity {
      public String objectid;
      public String playerid;
      public String playername;
      public String enemyid;
      public String enemyname;
      public String question;
  
  
      public mystatistik(String objectid, String playerid, String playername, String enemyid, String enemyname, String question) {
          this.objectid = objectid;
          this.playerid= playerid;
          this.playername= playername;
          this.enemyid= enemyid;
          this.enemyname= enemyname;
          this.question= question;
      }
  </code></pre>
  
  <p>add to arraylist</p>
  
  <pre><code>mystatistic mystatistic2 = new mystatistik(objectid,playerid, playername, enemyid, enemyname,question);
  mystatisticslist.add(mystatistic2);
  </code></pre>
  
  <p>now i want to get all unique "enemyid"'s from my arraylist "mystatisticslist". is this possible?
  thanks</p>