code: function _recordCollisions(collidable, collidingCollidables, elapsedTime) {
    return collidingCollidables.map(other => {
      const collision = {
        collidableA: collidable,
        collidableB: other,
        time: elapsedTime
      };
  
      // Record the fact that these objects collided (the ModelController may want to handle this).
      collision.collidableA.collisions.push(collision);
      collision.collidableB.collisions.push(collision);
  
      return collision;
    });
  }
docs: Create collision objects that record the time of collision and the collidables in the collision.
  
  Also record references to these collisions on the collidables.
  
  @param {Collidable} collidable
  @param {Array.<Collidable>} collidingCollidables
  @param {DOMHighResTimeStamp} elapsedTime
  @returns {Array.<Collision>}
  @private