What is the ultimate protopostmodernist novel?

Are there any novels that have elements of postmodern but had been created long before postmodern has ever appeared as a genre?

I would say that it is “Don Quixote”. It has features of postmodern such as irony, deconstruction and metafiction.

What are your examples of such literature?

BTW English is not my first language, I apologise for any mistakes.