function done(valid) {
      var canBeValidated = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : true;

      // Fixes GH#3903
      if (!canBeValidated || cellProperties.hidden === true) {
        callback(valid);
        return;
      }

      var col = cellProperties.visualCol;
      var row = cellProperties.visualRow;
      var td = instance.getCell(row, col, true);

      if (td && td.nodeName !== 'TH') {
        instance.view.wt.wtSettings.settings.cellRenderer(row, col, td);
      }

      callback(valid);
    }
Validate a single cell.

@param {String|Number} value
@param cellProperties
@param callback
@param source