docs: def _is_url_in_cache(*args, **kwargs):
      """ Return True if request has been cached or False otherwise. """
      # Only include allowed arguments for a PreparedRequest.
      allowed_args = inspect.getargspec(
          requests.models.PreparedRequest.prepare).args
      # self is in there as .prepare() is a method.
      allowed_args.remove('self')
  
      kwargs_cleaned = {}
      for key, value in dict(kwargs).items():
          if key in allowed_args:
              kwargs_cleaned[key] = value
  
      prepared_request = _prepare(*args, **kwargs_cleaned)
      request_hash = _get_hash(prepared_request)
      try:
          return requests_cache.get_cache().has_key(request_hash)
      except AttributeError as e:  # requests_cache not enabled
          if str(e) == "'Session' object has no attribute 'cache'":
              return False
          raise