'Handle incoming request.
Authenticate send downstream on success. Reject request if
we can\'t authenticate.'

def __call__(self, env, start_response):

    LOG.debug('Authenticating    user    token')
    ctx = context.get_current()
    authenticated = self.rpc_client.authenticated_to_backend(ctx)
    if authenticated:
        return self.app(env, start_response)
    else:
        return self._reject_request(env, start_response)
