Middlewares must take a MiddlewareInterface as their first constructor argument {Google\ApiCore\Middleware\ResponseMetadataMiddleware}, which represents the next middleware in the chain. This next middleware MUST be invoked by this MiddlewareInterface, and the result must be returned as part of the __invoke method implementation.

Represents a resource template that may or may not contain a leading slash, and if a leading slash is present may contain a trailing verb (":"). (Note that a trailing verb without a leading slash is not permitted).

Temporary class to support an interceptor-like interface until gRPC interceptor support is available.