nodes: 0, module; 1, function_definition; 2, function_name:get_sort_indicator; 3, parameters; 4, block; 5, identifier:self; 6, identifier:field; 7, expression_statement; 8, expression_statement; 9, if_statement; 10, return_statement; 11, comment:"""
          Returns a sort class for the active sort only. That is, if field is not
          sort_field, then nothing will be returned becaues the sort is not
          active.
          """; 12, assignment; 13, comparison_operator:field == self.sort_field; 14, block; 15, identifier:indicator; 16, identifier:indicator; 17, string; 18, identifier:field; 19, attribute; 20, expression_statement; 21, if_statement; 22, identifier:self; 23, identifier:sort_field; 24, assignment; 25, comparison_operator:self.sort_order == '-'; 26, block; 27, identifier:indicator; 28, string; 29, attribute; 30, string; 31, expression_statement; 32, string_content:sort-asc; 33, identifier:self; 34, identifier:sort_order; 35, string_content:-; 36, assignment; 37, identifier:indicator; 38, string; 39, string_content:sort-desc
code: def get_sort_indicator(self, field):
          """
          Returns a sort class for the active sort only. That is, if field is not
          sort_field, then nothing will be returned becaues the sort is not
          active.
          """
          indicator = ''
          if field == self.sort_field:
              indicator = 'sort-asc'
              if self.sort_order == '-':
                  indicator = 'sort-desc'
          return indicator