code: private boolean eligibleToFetch(List<String> columnsToSelect, String columnName)
      {
          return (columnsToSelect != null && !columnsToSelect.isEmpty() && columnsToSelect.contains(columnName))
                  || (columnsToSelect == null || columnsToSelect.isEmpty());
      }
docs: Eligible to fetch.
  
  @param columnsToSelect
  the columns to select
  @param columnName
  the column name
  @return true, if successful