function eachSelectedCheckboxCell(callback) {
    var selRange = instance.getSelectedRangeLast();

    if (!selRange) {
      return;
    }

    var topLeft = selRange.getTopLeftCorner();
    var bottomRight = selRange.getBottomRightCorner();

    for (var visualRow = topLeft.row; visualRow <= bottomRight.row; visualRow++) {
      for (var visualColumn = topLeft.col; visualColumn <= bottomRight.col; visualColumn++) {
        var cachedCellProperties = instance.getCellMeta(visualRow, visualColumn);

        if (cachedCellProperties.type !== 'checkbox') {
          return;
        }

        var cell = instance.getCell(visualRow, visualColumn);

        if (cell === null || cell === void 0) {
          callback(visualRow, visualColumn, cachedCellProperties);
        } else {
          var checkboxes = cell.querySelectorAll('input[type=checkbox]');

          if (checkboxes.length > 0 && !cachedCellProperties.readOnly) {
            callback(checkboxes);
          }
        }
      }
    }
  }
Call callback for each found selected cell with checkbox type.

@private
@param {Function} callback