A group life insurance policy shall contain in substance a provision that a copy of the application, if any, of the policyholder shall be attached to the policy when issued, that all statements made by the policyholder or by the persons insured shall be deemed representations and not warranties and that no statement made by any person insured shall be used in any contest unless a copy of the instrument containing the statement is or has been furnished to such person or in the event of death or incapacity of the insured person, to his beneficiary or personal representative.