code: function(event) {
      if (!(event && event.type)) {
        return false;
      }
      if (event.client && event.client !== this) {
        return false;
      }
      var meta = _clientMeta[this.id];
      var clippedEls = meta && meta.elements;
      var hasClippedEls = !!clippedEls && clippedEls.length > 0;
      var goodTarget = !event.target || hasClippedEls && clippedEls.indexOf(event.target) !== -1;
      var goodRelTarget = event.relatedTarget && hasClippedEls && clippedEls.indexOf(event.relatedTarget) !== -1;
      var goodClient = event.client && event.client === this;
      if (!meta || !(goodTarget || goodRelTarget || goodClient)) {
        return false;
      }
      return true;
    }
docs: Inspect an Event to see if the Client (`this`) should honor it for emission.
  @private