title: How do I arrange these objects in an arraylist
body: <p>I've been given an assignment to create an arena of objects that move, rotate and collide in JavaFX. My lecturer has instructed us to use a List for all objects that will appear in the game. All objects inherit from an abstract class with abstract methods for calculating position and rotation ect.
  Each object can also have attachments, for instance a 'whisker' that detects other objects and turns the robot accordingly.</p>
  
  <pre><code>public class Robot extends Object{
  private double energy;
  private ArrayList&lt;Object&gt; attachments = new ArrayList&lt;Object&gt;();
  
  public class Whisker extends Object{
  private Object attached;
  private Line whisker;
  </code></pre>
  
  <p>Should each robot have an arraylist of 'attachments' that are connected to the robot? </p>
  
  <p>Each attachment would also need to know which robot it is connected to. </p>
  
  <p>Will this cause issues? or will this effectively create a double linked between objects and attachments? </p>
  
  <p>or should all objects have their own array lists?</p>