Where, in an action for a broker's commissions in negotiating a hotel lease, the court charged that the jury could find for the plaintiff, either if plaintiff's agency had been revoked or if the revocation was made in bad faith, the refusal of certain instructions, "that under the evidence plaintiff's employment to procure a tenant was revoked by what took place in a certain interview between plaintiff and defendant," could not be sustained on the theory that a revocation, if in fraud of plaintiff's rights, would not amount to a revocation. Cadi-gan v. Crabtree, 192 Mass. 230, 78 N. E. 412. Compare Sec. 22.