title: bullet collision callback between 2 bodies
body: <p>I have 2 objects, a sphere and a box that, when one collides with the other, will do some action (i.e. destroy the box).</p>
  
  <p>I have tried several ways:</p>
  
  <ul>
  <li>checkCollideWith always returns true;</li>
  <li>contactPairTest - this I do not understand how to use.
  It takes 3 arguments, the 2 objects and a callback. I thought that the callback can be any function in my code, but it doesn't work like that.</li>
  </ul>
  
  <p>Could someone please give an example of how to call a method, for example CollissionResult(), when 2 btRigidBodies collide (i.e. bodyA and bodyB)?</p>