code: def ordered_cols(self, columns, section):
          
          columns = list(columns)  # might be a tuple
          fixed_cols = [self.key]
          if section.lower() == "different":
              fixed_cols.extend([Differ.CHANGED_MATCH_KEY, Differ.CHANGED_OLD, Differ.CHANGED_NEW])
          map(columns.remove, fixed_cols)
          columns.sort()
          return fixed_cols + columns
docs: Return ordered list of columns, from given columns and the name of the section