function DataZoom(model, ecModel, api) {

	        /**
	         * @private
	         * @type {module:echarts/component/helper/BrushController}
	         */
	        (this._brushController = new BrushController(api.getZr()))
	            .on('brush', zrUtil.bind(this._onBrush, this))
	            .mount();

	        /**
	         * @private
	         * @type {boolean}
	         */
	        this._isZoomActive;
	    }
@public
@param {module:echarts/model/Global} ecModel
@return {number} records. always >= 1.