code: def complement(self, alphabet):
          
          self._addsink(alphabet)
          for state in self.automaton.states():
              if self.automaton.final(state) == fst.Weight.One(self.automaton.weight_type()):
                  self.automaton.set_final(state, fst.Weight.Zero(self.automaton.weight_type()))
              else:
                  self.automaton.set_final(state, fst.Weight.One(self.automaton.weight_type()))
docs: Returns the complement of DFA
          Args:
              alphabet (list): The input alphabet
          Returns:
              None