def register_extensions(self, controller):

        extensions = getattr(controller, 'wsgi_extensions', [])
        for method_name, action_name in extensions:
            # Look up the extending method
            extension = getattr(controller, method_name)

            if action_name:
                # Extending an action...
                if action_name not in self.wsgi_action_extensions:
                    self.wsgi_action_extensions[action_name] = []
                self.wsgi_action_extensions[action_name].append(extension)
            else:
                # Extending a regular method
                if method_name not in self.wsgi_extensions:
                    self.wsgi_extensions[method_name] = []
                self.wsgi_extensions[method_name].append(extension)
Registers controller extensions with this resource.
dataset/ETHPy150Open openstack/rack/rack/api/wsgi.py/Resource.register_extensions