ctor(options) {
    // do super ctor
    this._super();

    // apply options
    if (_.isObject(options)) {
      this.setOptions(options);
    }
  }
*************************************************************************
Light
var Light = cc.Node
Light.create()
 - lights are drawn as a part of a batch, never individually
 - light default behavior is radial based on width/height
**************************************************************************