code: def rename(self, names, prefix):
          
          if names:
              if len(names) != len(self._contents):
                  raise InputError('Attribute count mismatch.')
              if self.has_duplicates(names):
                  raise InputError('Attributes are ambiguous.')
          else:
              # If the attributes are not renamed, but the relation / prefix is,
              # there is a risk of creating two or more attributes with the
              # same name and prefix.
              if prefix and self.has_duplicates(self.names):
                  raise AttributeReferenceError('Attributes are ambiguous.')
  
          replacement = []
          for old, name in itertools.zip_longest(self._contents, names):
              new_name = name or old.name
              new_prefix = prefix or old.prefix
              replacement.append(Attribute(new_name, new_prefix))
          self._contents = replacement
docs: Rename the Attributes' names, prefixes, or both. If names or prefix
          evaluates to None, the old version is used.
          Resulting names must be unambiguous.
          :param names: A list of new names for each attribute or an empty list.
          :param prefix: A new prefix for the name or None