“An author who is being sued for a coming novel that J.D. Salinger says is ‘a rip-off pure and simple’ of ‘The Catcher in the Rye’ will argue that his book is a legally protected literary commentary on Mr. Salinger’s original novel.” The author “says that his novel is not a sequel … but rather ‘a complex and undeniably transformative exposition about one of our nation’s most famous authors, J.D. Salinger, and his best known creation, Holden Caulfield.'”