code: def get_most_common_states(state_iterable):
      
      state_counter = Counter()
      for states in state_iterable:
          state_counter.update(states)
      max_count = state_counter.most_common(1)[0][1]
      return {state for (state, count) in state_counter.items() if count == max_count}
docs: Gets the set of most common states among the state sets contained in the iterable argument
      :param state_iterable: iterable of state sets
      :return: set of most common states