function get(opt, path) {
	        path = path.split(',');
	        var obj = opt;
	        for (var i = 0; i < path.length; i++) {
	            obj = obj && obj[path[i]];
	            if (obj == null) {
	                break;
	            }
	        }
	        return obj;
	    }
@param {module:echarts/ExtensionAPI} api
@param {Object} [opts]
@param {string} [opts.text]
@param {string} [opts.color]
@param {string} [opts.textColor]
@return {module:zrender/Element}