is well-established that an "assignee steps into the shoes of the assignor, and has all of the rights of the assignor." Mut. of Enumclaw Ins. Co. v. USF Ins. Co., 164 Wn.2d 411, 191 P.3d 866, 874-75 (Wash. 2008); Fed. Fin. Co., 949 P.2d at 417 ("[A]n assignee's rights are coextensive with those of the assign