code: def _format_message(code_name, details):
      if details is None:
          return code_name
      else:
          return "%s: %s" % (code_name, details)
  
file_path: tensorboard/tensorboard/errors.py
label_desc: Use image node_id 1 for calling a global function with example usage: _format_message(code_name, details) and returns: code_name, unknown