class_docstr: FileWriter for test.
  
  TensorFlow FileWriter uses TensorFlow's Protobuf Python binding
  which is largely discouraged in TensorBoard. We do not want a
  TB.Writer but require one for testing in integrational style
  (writing out event files and use the real event readers).
docstr: Convenience for writing a simple summary for a given tag.
docstr_tok: ["Convenience","for","writing","a","simple","summary","for","a","given","tag","."]
code: def add_test_summary(self, tag, simple_value=1.0, step=None):
      """Convenience for writing a simple summary for a given tag."""
      value = summary_pb2.Summary.Value(
          tag=tag, simple_value=simple_value
      )
      summary = summary_pb2.Summary(value=[value])
      self.add_summary(summary, global_step=step)
  
imports: import threading
  import tensorflow
  from tensorboard.compat.proto import event_pb2
  from tensorboard.compat.proto import graph_pb2
  from tensorboard.compat.proto import meta_graph_pb2
  from tensorboard.compat.proto import summary_pb2
  from tensorboard.util import tb_logging
label_desc: Use image node_id 2 for calling the FileWriter obj's underlying member method code with example usage: obj.add_test_summary(tag, simple_value, step) without return types