code: def check_synced(localval, comm=None):
      
      comm = comm or MPI.COMM_WORLD
      vals = comm.gather(localval)
      if comm.rank == 0:
          assert all(val==vals[0] for val in vals[1:])
docs: It's common to forget to initialize your variables to the same values, or
      (less commonly) if you update them in some other way than adam, to get them out of sync.
      This function checks that variables on all MPI workers are the same, and raises
      an AssertionError otherwise
  
      Arguments:
          comm: MPI communicator
          localval: list of local variables (list of variables on current worker to be compared with the other workers)