docs: def __create_chron_cols(metadata):
          """
          Use to collected chron metadata to create the chron columns
          :param dict metadata: key: variable, val: unit (optional)
          :return list: list of one dict per column
          """
          chron_col_list = []
          chron_col_ct = 1
          for variableName, unit in metadata.items():
              temp_dict = OrderedDict()
              temp_dict['column'] = chron_col_ct
              temp_dict['variableName'] = variableName
              temp_dict['unit'] = unit
              chron_col_list.append(copy.deepcopy(temp_dict))
              chron_col_ct += 1
  
          return chron_col_list