"Western Sky was an online payday lender owned by Martin Webb, who was a member of the Cheyenne River Sioux Tribe. Western Sky's offices were also located on the Cheyenne River Indian Reservation in South Dakota. Western Sky's loan agreements included provision requiring customers with dis-putes to undergo binding arbitration""The loan agreements also included the follow-ing provision: "This Loan Agreement is subject solely to the exclusive laws and jurisdiction of the Cheyenne River Sioux Tribe, Cheyenne River Indian Reservation. By executing this Loan Agree-ment, you, the borrower, hereby acknowledge and consent to be bound to the terms of this Loan Agreement, consent to the sole subject matter and personal jurisdiction of the Cheyenne River Sioux Tribal Court, and that no other state or federal law or regulation shall apply to this Loan Agreement, its enforcement or interpretation."Is this contract enforceable? "