'Called by self._router after matching the incoming request to a route
and putting the information into req.environ.  Either returns 404,
501, or the routed WSGI app\'s response.'

@staticmethod
@webob.dec.wsgify
def _dispatch(req):

    match = req.environ['wsgiorg.routing_args'][1]
    if (not match):
        implemented_http_methods = ['GET', 'HEAD', 'POST', 'PUT', 'DELETE', 'PATCH']
        if (req.environ['REQUEST_METHOD'] not in implemented_http_methods):
            return webob.exc.HTTPNotImplemented()
        else:
            return webob.exc.HTTPNotFound()
    app = match['controller']
    return app
