Method _ship

seq_logger.js:154–178

* * @returns {Promise }

()

         * @returns {Promise<boolean>}
         */
        _ship() {
            if (this._queue.length === 0) {
                return Promise.resolve(false);
            }

            let wait = this._activeShipper || Promise.resolve(false);
            let shipper = this._activeShipper = wait
                .then(() => {
                    let more = drained => {
                        if (drained) {
                            // If the queue was drained, let the timer
                            // push us forwards.
                            return true;
                        }
                        return this._sendBatch().then(d => more(d));
                    }
                    return this._sendBatch().then(drained => more(drained));
                })
                .then(() => this._reset(shipper), e => {
                    this._onError(e);
                    this._reset(shipper);
                });

            return shipper;
        }

        _sendBatch() {
            if (this._queue.length === 0) {