In Central Trust Co. v. Chicago Auditorium, 240 U. S. 581, 592, 36 S. Ct. 412, 60 L. Ed. 811, L. R. A. 1917B, 580 (1916), the Supreme Court approved the language of Judge Lowell in Re Pettingill & Co. (D. C.) 137 F. 143, 147, that: "The test of provability under the act of 1898 may be stated thus: If the bankrupt, at the time of bankruptcy, by disenabling himself from performing the contract in question, and by repudiating its obligation, could give the proving creditor the right to maintain at once a suit in which damages could be assessed at law or in equity, then the creditor can prove in bankruptcy on the ground that bankruptcy is the equivalent of disenablement and repudiation. For the assessment of damages proceedings may be directed by the court under section 63b of the Bankruptcy Act."