Please, clarify WebSocket description

[alsemenov]

Current description for class dart:io:WebSocket is quite short.
Please, specify the following:

• The WebSockets specification and version (probably some draft) which is implemented by dart:io:WebSocket class. This is important for heterogeneous communications. The other side (which might be not Dart) should know what expect.
• Which protocols and extensions are supported?
• Whether messages (especially List<int>) are transfered without splitting or joining with another messages
• The WebSocket life cycle, like readyState (?) is CONNECTING after call to connect, OPEN after future returned by connect completes, etc. (BTW CONNECTING seems to be redundant in this case).
• How the readyState of paired instance is affected, when WebSocket is closed or closing
• If done event is received on WebSocket (which implements Stream) is it necessary to close the WebSocket explicitly?
• Will peer instance receive done event after call to close?
• WebSocket implements StreamSink, however only String and List<int> are allowed as events, which formally violates contract of StreamSink. What will happen if events other than String and List<int> are supplied to method add? Why it is not possible to send events of some simple types like int, bool, Map, etc?

[alsemenov]

Additional questions:

• if only String and List are allowed as events, then which types are allowed as errors?
• WebSocket is a single-subscription Stream. If some listener have subscribed to WebSocket and then unsubscribed, is it necessary to call close explicitly? or it is called implicitly?