@Override
 public ColumnSnapshot findByNameAndBoardId(String name, long boardId) {
   Column column = columnRepository.findByBoardIdAndName(boardId, name);
   return column == null ? null : column.toSnapshot();
 }
 @Override
 public ColumnSnapshot findById(long columnId) {
   Column column = columnRepository.findOne(columnId);
   return column == null ? null : column.toSnapshot();
 }