code: function onPointerUpCaptured( tracker, event ) {
          var pointsList = tracker.getActivePointersListByType( getPointerType( event ) );
          if ( pointsList.getById( event.pointerId ) ) {
              handlePointerUp( tracker, event );
          }
          $.stopEvent( event );
      }
docs: This handler is attached to the window object (on the capture phase) to emulate mouse capture.
  onPointerUp is still attached to the tracked element, so stop propagation to avoid processing twice.
  
  @private
  @inner