docs: function (markLineModel, ecModel, api) {
          ecModel.eachSeries(function (seriesModel) {
              var mlModel = seriesModel.markLineModel;
              if (mlModel) {
                  var mlData = mlModel.getData();
                  var fromData = mlModel.__from;
                  var toData = mlModel.__to;
                  // Update visual and layout of from symbol and to symbol
                  fromData.each(function (idx) {
                      updateSingleMarkerEndLayout(fromData, idx, true, seriesModel, api);
                      updateSingleMarkerEndLayout(toData, idx, false, seriesModel, api);
                  });
                  // Update layout of line
                  mlData.each(function (idx) {
                      mlData.setItemLayout(idx, [
                          fromData.getItemLayout(idx),
                          toData.getItemLayout(idx)
                      ]);
                  });
  
                  this.markerGroupMap.get(seriesModel.id).updateLayout();
  
              }
          }, this);
      }