code: def experiment_id(environ):
      """Determine the experiment ID associated with a WSGI request.
  
      Each request to TensorBoard has an associated experiment ID, which is
      always a string and may be empty. This experiment ID should be passed
      to data providers.
  
      Args:
        environ: A WSGI environment `dict`. For a Werkzeug request, this is
          `request.environ`.
  
      Returns:
        A experiment ID, as a possibly-empty `str`.
      """
      return environ.get(_experiment_id.WSGI_ENVIRON_KEY, "")
  
imports: import threading
  from bleach.sanitizer import Cleaner
  import markdown
  from tensorboard import context
  from tensorboard.backend import experiment_id
  from tensorboard.util import tb_logging
label_desc: Use image node_id 5 for calling a global function with example usage: experiment_id(environ) and returns: environ