code: function(dataSource) {
          while (dataSource) {
              if (/treeview/i.test(dataSource.$$CLASS_NAME)) {
                  dataSource.treeview = this;
              }
              dataSource = dataSource.dataSource;
          }
      }
docs: @summary Initialize a new instance.
  @desc Set up {@link DataSourceTreeviewSorter} access to this object. Access is provided to the whole object although only instance variables `joined`, `idColumn`, and `parentIdColumn` are needed by the sorter. The two ID columns are passed to the {@link DataSourceDepthSorter} constructor. (If dataSource is not the sorter, this is not used but harmless.)
  
  Note that all ancestor classes' `initialize` methods are called (top-down) before this one. See {@link http://npmjs.org/extend-me} for more info.
  @param dataSource
  @memberOf DataSourceTreeview#