'Initializes this application with the given URL mapping.
Args:
url_mapping: list of (URI regular expression, RequestHandler) pairs
(e.g., [(\'/\', ReqHan)])
debug: if true, we send Python stack traces to the browser on errors'

def __init__(self, url_mapping, debug=False):

    self._init_url_mappings(url_mapping)
    self.__debug = debug
    WSGIApplication.active_instance = self
    self.current_request_args = ()
