function getDisplayName(grid, gridCol) {
        if (grid.options.exporterHeaderFilter) {
          return grid.options.exporterHeaderFilterUseName ?
            grid.options.exporterHeaderFilter(gridCol.name) :
            grid.options.exporterHeaderFilter(gridCol.displayName);
        }

        return gridCol.headerCellFilter ?
          $filter(gridCol.headerCellFilter)(gridCol.displayName) :
          gridCol.displayName;
      }
@ngdoc function
@name formatFieldAsExcel
@methodOf  ui.grid.exporter.service:uiGridExporterService
@description Renders a single field as a excel-ified field
@param {field} field the field to be excel-ified,
may be of any type
@returns {string} a excel-ified version of the field