In National Labor Relations Board v. Reed Prince Mfg. Co., 1 Cir., 118 F.2d 874, certiorari denied 313 U.S. 595, 61 S.Ct. 1119, 85 L.Ed. 1549, it was held that an employer's insistence on a provision in a contract with a bargaining agent, that during the period of the contract or at any future time the employees and the union would not request or demand a closed shop agreement or check-off system, warranted the National Labor Relations Board in inferring that the employer was not actuated by a genuine desire to reach an accord with the bargaining representative.