code: function buildDataTable() {
        var self = this;
  
        var dataTable = new google.visualization.DataTable();
  
        _.each(self.columns, function (value) {
          dataTable.addColumn(value);
        });
  
        if (!_.isEmpty(self.rows)) {
          dataTable.addRows(self.rows);
        }
  
        return dataTable;
      }
docs: Initialize the datatable and add the initial data.
  
  @link https://developers.google.com/chart/interactive/docs/reference#DataTable
  @return object