docs: def _unparse_change_record(self, modlist):
          """
          :type modlist: List[Tuple]
          :param modlist: List of additions (2-tuple) or modifications (3-tuple)
          """
          mod_len = len(modlist[0])
          self._unparse_changetype(mod_len)
  
          for mod in modlist:
              if len(mod) != mod_len:
                  raise ValueError("Subsequent modlist item of wrong length")
  
              if mod_len == 2:
                  mod_type, mod_vals = mod
              elif mod_len == 3:
                  mod_op, mod_type, mod_vals = mod
                  self._unparse_attr(MOD_OPS[mod_op], mod_type)
  
              for mod_val in mod_vals:
                  self._unparse_attr(mod_type, mod_val)
  
              if mod_len == 3:
                  self._output_file.write(b'-' + self._line_sep)