code: private Column createColumnFromCell(Sheet sheet, Cell cell) {
      if (cell.getCellTypeEnum() == CellType.STRING) {
        return Column.create(
            cell.getStringCellValue(),
            cell.getColumnIndex(),
            getColumnDataFromSheet(sheet, cell.getColumnIndex()));
      } else {
        throw new MolgenisDataException(
            String.format(
                "Celltype [%s] is not supported for columnheaders", cell.getCellTypeEnum()));
      }
    }
docs: Specific columntypes are permitted in the import. The supported columntypes are specified in
  the method.
  
  @param sheet worksheet
  @param cell cell on worksheet
  @return Column