def METHOD_NAME(name=None):
  """An op which returns the number of MPI processes.
  This is equivalent to running `MPI_Comm_size(MPI_COMM_WORLD, ...)` to get the
  size of the global communicator.
  Returns:
    An integer scalar containing the number of MPI processes.
  """
  return gen_mpi_ops.mpi_size(name=name)