code: function removeCellSelections () {
          if (editable) {
              var selectedCells = editable.querySelectorAll('.' + selection_class);
              if (selectedCells.length > 0) {
                for (var i = 0; i < selectedCells.length; i++) {
                    dom.removeClass(selectedCells[i], selection_class);
                }
              }
          }
      }
docs: remove all selection classes