function getGlobalExtent(coordSys, dimIndex) {
    var rect = coordSys.getRect();
    return [rect[XY[dimIndex]], rect[XY[dimIndex]] + rect[WH[dimIndex]]];
}
Get data indices for show tooltip content
@param {Array.<string>|string} dim  single coordinate dimension
@param {number} value axis value
@param {module:echarts/coord/single/SingleAxis} baseAxis  single Axis used
    the themeRiver.
@return {Object} {dataIndices, nestestValue}