lib/altshift/promise.js
function () {
        if (!this.finished && this._canceller) {
            var error = this._canceller();
            if (!(error instanceof Error)) {
                error = new Error(error);
            }
            return this.emitError(error);
        }
        return false;
    }
function () {
        if (!this.finished && this._canceller) {
            var error = this._canceller();
            if (!(error instanceof Error)) {
                error = new Error(error);
            }
            return this.emitError(error);
        }
        return false;
    }
function ( ) { if ( ! this . finished && this . _canceller ) { var error = this . _canceller ( ) ; if ( ! ( error instanceof Error ) ) { error = new Error ( error ) ; } return this . emitError ( error ) ; } return false ; }
Cancel the promise

@return {boolean} true if error was handled
Cancel the promise