code: def reorder_keys(self, keys):
          '''Accepts a :keys: parameter, an iterable of keys in the
          desired new order. The :keys: parameter must contain all
          existing keys.'''
          if len(keys) != len(self._set):
              raise ValueError('The supplied number of keys does not match.')
          if set(keys) != self._set:
              raise ValueError('The supplied keys do not match the current set of keys.')
          self._keys = list(keysf reorder_keys(self, keys):
          '''Accepts a :keys: parameter, an iterable of keys in the
          desired new order. The :keys: parameter must contain all
          existing keys.'''
          if len(keys) != len(self._set):
              raise ValueError('The supplied number of keys does not match.')
          if set(keys) != self._set:
              raise ValueError('The supplied keys do not match the current set of keys.')
          self._keys = list(keys)
docs: Accepts a :keys: parameter, an iterable of keys in the
          desired new order. The :keys: parameter must contain all
          existing keys.