The WSGI spec requires that any callable object that has a .close() method must have that called once all data has been returned. This is not currently implemented.
The WSGI spec requires start_reponse to have the signature start_response(status, response_headers, exc_info=None). Currently the exc_info argument is not supported because I don't know how.
The error handling specified in PEP 333 is not properly implemented.
