Given the task definition and input, reply with output. This task is about creating an unanswerable question based on a given passage. Construct a question that looks relevant to the given context but is unanswerable. Following are a few suggestions about how to create unanswerable questions:
(i) create questions which require satisfying a constraint that is not mentioned in the passage
(ii) create questions which require information beyond what is provided in the passage in order to answer
(iii) replace an existing entity, number, date mentioned in the passage with other entity, number, date and use it in the question
(iv) create a question which is answerable from the passage and then replace one or two words by their antonyms or insert/remove negation words to make it unanswerable.

Passage: Notably, the most broadly influential innovation of 20th-century American tort law was the rule of strict liability for defective products, which originated with judicial glosses on the law of warranty. In 1963, Roger J. Traynor of the Supreme Court of California threw away legal fictions based on warranties and imposed strict liability for defective products as a matter of public policy in the landmark case of Greenman v. Yuba Power Products. The American Law Institute subsequently adopted a slightly different version of the Greenman rule in Section 402A of the Restatement (Second) of Torts, which was published in 1964 and was very influential throughout the United States. Outside the U.S., the rule was adopted by the European Economic Community in the Product Liability Directive of July 1985 by Australia in July 1992 and by Japan in June 1994.
What case occurred in 1994?