code: def _split_sequences_multitraj(dtrajs, lag):
      
      n = number_of_states(dtrajs)
      res = []
      for i in range(n):
          res.append([])
      for dtraj in dtrajs:
          states, seqs = _split_sequences_singletraj(dtraj, n, lag)
          for i in range(len(states)):
              res[states[i]].append(seqs[i])
      return res
docs: splits the discrete trajectories into conditional sequences by starting state
  
      Parameters
      ----------
      dtrajs : list of int-iterables
          discrete trajectories
      nstates : int
          total number of discrete states
      lag : int
          lag time