Function shutdown

examples/io/streams/modules/streams.js:951–963

(isError, error)

		}

		function shutdown(isError, error) {
			if (shuttingDown === true) {
				return;
			}
			shuttingDown = true;

			if (dest.state === 'writable' && WritableStreamCloseQueuedOrInFlight(dest) === false) {
				waitForWritesToFinish().then(() => finalize(isError, error));
			}
			else {
				finalize(isError, error);
			}
		}
		function finalize(isError, error) {
			WritableStreamDefaultWriterRelease(writer);
			ReadableStreamDefaultReaderRelease(reader);