What is the test for successorship in the context of a claim for wrongful dismissal?

"Courts that have considered the successorship question in a labor context have found a multiplicity of factors to be relevant. These include: 1) whether [27 Cal.App.4th 1028] the successor company had notice of the charge, 2) the ability of the predecessor to provide relief, 3) whether there has been a substantial continuity of business operations, 4) whether the new employer uses the same plant, 5) whether he uses the same or substantially the same work force, 6) whether he uses the same or substantially the same supervisory personnel, 7) whether the same jobs exist under substantially the same working conditions, 8) whether he uses the same machinery, equipment and methods of production and 9) whether he produces the same product." (EEOC v. MacMillan Bloedel Containers, Inc., supra, 503 F.2d 1086, 1904, citations omitted.)