_deletePendingReqStream(id, origin) {
		const reqStream = this.pendingReqStreams.get(id);
		const pass = reqStream ? reqStream.stream : undefined;
		this.pendingReqStreams.delete(id);

		if (pass) {
			this._destroyStreamIfPossible(pass, `Stream closed by ${origin}`);
		}
	}
Internal method to delete a pending request stream from `pendingReqStreams`
and destroy it (if not already ended) with error.

@param {String} id ID of the stream in `pendingReqStreams`
@param {String} origin NodeID of the origin of the destroy request

@memberof Transit