8 years before Leonardo DiCaprio stole his first secret from his victim's dream in Inception, Don Rosa had already Donald Duck in Scrooge McDuck's dreams, defending his secrets from the invaders the Beagles Boys. Pure coincidence? or is Christopher Nolan a big fun of the Duck? He did pitch the idea of the movie roughly at the same time…
You can read the whole comic here
Uncle Scrooge in the Dream of a Lifetime