Joint tenancy in and to a safe deposit box may be created by contract, with two or more persons named as lessees. The terms of the contract may provide that any one or more of the lessees, or the survivor or survivors of such lessee or lessees, shall have access and entry to the safe deposit box and the right to remove the contents from such box whether the other lessee or lessees be living, incompetent or dead. If the contents are removed as provided by the contract, the lessor shall not be liable for the removal of the contents.