code: def pretty(self):
          
          lines = list()
          for index, record in enumerate(self._records):
              lines.append(("record {0}".format(index+1),))
              lines.append(("  type", repr(record.type)))
              lines.append(("  name", repr(record.name)))
              lines.append(("  data", repr(record.data)))
          lwidth = max([len(line[0]) for line in lines])
          lines = [(line[0].ljust(lwidth),) + line[1:] for line in lines]
          lines = [" = ".join(line) for line in lines]
          return ("\n").join([line for line in lines])
docs: Returns a message representation that might be considered
          pretty-printable.