docs: function _pickContent(targetRows, startColIndex, endColIndex) {
    const limitColIndex = endColIndex + 1;
    const cells = [].concat(...targetRows.map(rowData => rowData.slice(startColIndex, limitColIndex)));
    const foundCellData = cells.filter(({content}) => content && content !== BASIC_CELL_CONTENT);
  
    return foundCellData.length ? foundCellData[0].content : BASIC_CELL_CONTENT;
  }