code: function buildCssString(options) {
      var styles = [
          styleGen.outline(options.outline),
          styleGen.frozenBorder(options.frozenBorder),
          styleGen.scrollbar(options.scrollbar),
          styleGen.heightResizeHandle(options.heightResizeHandle),
          styleGen.pagination(options.pagination),
          styleGen.selection(options.selection)
      ];
      var area = options.area;
      var cell = options.cell;
  
      styles = styles.concat([
          styleGen.headArea(area.header),
          styleGen.bodyArea(area.body),
          styleGen.summaryArea(area.summary)
      ]);
  
      if (cell) {
          styles = styles.concat([
              styleGen.cell(cell.normal),
              styleGen.cellDummy(cell.dummy),
              styleGen.cellEditable(cell.editable),
              styleGen.cellHead(cell.head),
              styleGen.cellRowHead(cell.rowHead),
              styleGen.cellSummary(cell.summary),
              styleGen.cellOddRow(cell.oddRow),
              styleGen.cellEvenRow(cell.evenRow),
              styleGen.cellRequired(cell.required),
              styleGen.cellDisabled(cell.disabled),
              styleGen.cellInvalid(cell.invalid),
              styleGen.cellCurrentRow(cell.currentRow),
              styleGen.cellSelectedHead(cell.selectedHead),
              styleGen.cellSelectedRowHead(cell.selectedRowHead),
              styleGen.cellFocused(cell.focused),
              styleGen.cellFocusedInactive(cell.focusedInactive)
          ]);
      }
  
      return styles.join('');
  }
docs: build css string with given options.
  @param {Object} options - options
  @returns {String}
  @ignore