n the Fourth Proviso. Moreover, the Debtors' interpretation renders language in the indenture superfluous, which is a common sign of ambiguity. See RJE Corp. v. Northville Indus. Corp., 329 F.3d 310, 314 (2d Cir. 2003) ( [HN3] in assessing ambiguity, courts consider the entire contract "to safeguard agai