code: def __init__(self, application):
      """Initializes an `ExperimentIdMiddleware`.
  
      Args:
        application: The WSGI application to wrap (see PEP 3333).
      """
      self._application = application
      # Regular expression that matches the whole `/experiment/EID` prefix
      # (without any trailing slash) and captures the experiment ID.
      self._pat = re.compile(
          r"/%s/([^/]*)" % re.escape(_EXPERIMENT_PATH_COMPONENT)
      )
  
imports: import re
label_desc: Use image node_id 1 to create a new ExperimentIdMiddleware object  with example: obj = ExperimentIdMiddleware(application)