message: `should_record_summaries()` should return false is no summary writer has been
  set.
diff: @@ -78,16 +78,21 @@ _summary_state = _SummaryState()
  def _should_record_summaries_internal(default_state):
  """Returns boolean Tensor if summaries should/shouldn't be recorded.
  - Now the summary condition is decided by logical "and" of two conditions:
  - ctx.summary_recording and ctx.summary_recording_distribution_strategy. The
  - former one is usually set by user, and the latter one is controlled by
  - DistributionStrategy (tf.distribute.ReplicaContext).
  + Now the summary condition is decided by logical "and" of below conditions:
  + First, summary writer must be set. Given this constraint is met,
  + ctx.summary_recording and ctx.summary_recording_distribution_strategy.
  + The former one is usually set by user, and the latter one is controlled
  + by DistributionStrategy (tf.distribute.ReplicaContext).
  Args:
  - default_state: can be True or False. The default summary behavior when user
  - does not specify ctx.summary_recording and
  - ctx.summary_recording_distribution_strategy is True.
  + default_state: can be True or False. The default summary behavior when
  + summary writer is set and the user does not specify
  + ctx.summary_recording and ctx.summary_recording_distribution_strategy
  + is True.
  """
  + if _summary_state.writer is None:
  + return constant_op.constant(False)
  +
  resolve = lambda x: x() if callable(x) else x
  cond_distributed = resolve(_summary_state.is_recording_distribution_strategy)
  cond = resolve(_summary_state.is_recording)
  