message: Fix `TPUMirroredVariable.device` when called within a TPU context.
diff: @@ -904,7 +904,7 @@ class TPUMirroredVariable(trackable.Trackable):
  @property
  def device(self):
  - return self._get().device
  + return self.handle.device
  def eval(self, session=None):
  return self.primary.eval(session)
  