The Senior Agent, for itself and on behalf of each other Senior Claimholder, and each Subordinated Claimholder agree that it will not (and hereby waives any right to), directly or indirectly, contest or support any other person in contesting, in any proceeding (including any Insolvency Proceeding), (i) the validity, priority, enforceability or allowance of any claims of any of the Senior Claimholders or any of the Subordinated Claimholders, as the case may be, (ii) the priority, validity, or enforceability of a Lien held by or on behalf of any of the Senior Claimholders in any Collateral or (subject to the terms of this Agreement) by or on behalf of any of the Subordinated Claimholders in any Collateral, as the case may be, or (iii) the validity or enforceability of the provisions of this Agreement; provided , however that nothing in this Agreement shall be construed to prevent or impair the rights of the Senior Agent, any other Senior Claimholder, the Subordinated Agent or any other Subordinated Claimholder to enforce the terms of this Agreement.