. District of Columbia, 713 F.3d 120, 126, 404 U.S. App. D.C. 316 (D.C. Cir. 2013) (surveying how Wal-Mart has changed the class action landscape); Elizabeth Tippett, Robbing A Barren Vault: The Implications of Dukes v. Wal-Mart for Cases Challenging Subjective Employment Practices, 29 Hofstra Lab. & Emp. L.J. 4