code: function (evt) {
      var data = this.data;
      this.twoWayEmit(EVENTS.MOUSEUP);
  
      // If intersected entity has changed since the cursorDown, still emit mouseUp on the
      // previously cursorUp entity.
      if (this.cursorDownEl && this.cursorDownEl !== this.intersectedEl) {
        this.intersectedEventDetail.intersection = null;
        this.cursorDownEl.emit(EVENTS.MOUSEUP, this.intersectedEventDetail);
      }
  
      if ((!data.fuse || data.rayOrigin === 'mouse') &&
          this.intersectedEl && this.cursorDownEl === this.intersectedEl) {
        this.twoWayEmit(EVENTS.CLICK);
      }
  
      this.cursorDownEl = null;
      if (evt.type === 'touchend') { evt.preventDefault(); }
    }
docs: Trigger mouseup if:
  - Not fusing (mobile has no mouse).
  - Currently intersecting an entity.
  - Currently-intersected entity is the same as the one when mousedown was triggered,
  in case user mousedowned one entity, dragged to another, and mouseupped.