message: Apparently list() no longer takes a keyword argument (Python 3.6->3.7). Remove that from the test.
diff: @@ -57,7 +57,7 @@ class HasList(training.Model):
  [core.Dense(10)]))
  self.layer_list.extend(
  data_structures.List(
  - list(sequence=[core.Dense(11)]) + [core.Dense(12)]))
  + list([core.Dense(11)]) + [core.Dense(12)]))
  self.layers_with_updates = data_structures.List(
  sequence=(normalization.BatchNormalization(),))
  