src/data/helper/linkList.js
function getLinkedData(dataType) {
    var mainData = this[MAIN_DATA];
    return (dataType == null || mainData == null)
        ? mainData
        : mainData[DATAS][dataType];
}
function getLinkedData(dataType) {
    var mainData = this[MAIN_DATA];
    return (dataType == null || mainData == null)
        ? mainData
        : mainData[DATAS][dataType];
}
function getLinkedData ( dataType ) { var mainData = this [ MAIN_DATA ] ; return ( dataType == null || mainData == null ) ? mainData : mainData [ DATAS ] [ dataType ] ; }
Supplement method to List.

@public
@param {string} [dataType] If not specified, return mainData.
@return {module:echarts/data/List}
Supplement method to List .