docs: def addTransitions(self, state, transitions):
          """
          Create a new L{TransitionTable} with all the same transitions as this
          L{TransitionTable} plus a number of new transitions.
  
          @param state: The state for which the new transitions are defined.
          @param transitions: A L{dict} mapping inputs to output, nextState
              pairs.  Each item from this L{dict} will define a new transition in
              C{state}.
  
          @return: The newly created L{TransitionTable}.
          """
          table = self._copy()
          state = table.table.setdefault(state, {})
          for (input, (output, nextState)) in transitions.items():
              state[input] = Transition(output, nextState)
          return table