Add onConnected (dart-lang/sse#39)

Closes https://github.com/dart-lang/sse/issues/38

Before this change consumers of `package:sse` must assume the connection is established immediately. Add `onConnected` to prevent this assumption and so that UIs can react accordingly.
4 files changed
tree: 109007cc634df73dc23fc7684a414ee35d847e39
  1. pkgs/