def Serial(*fns):  # pylint: disable=invalid-name
  """Combines generator functions into one that runs them serially."""
  def composed_fns(generator=None):
    for f in fastmath.tree_flatten(fns):
      generator = f(generator)
    return generator
  return composed_fns
Combines generator functions into one that runs them serially.
trax/data/inputs.py