message: Update BUILD visibility.
diff: @@ -88,6 +88,9 @@ tpu_py_test(
  pytype_library(
  name = "device_assignment",
  srcs = ["device_assignment.py"],
  + visibility = [
  + "//tensorflow:internal",
  + ],
  deps = [
  ":topology",
  "//tensorflow/python:platform",
  