Add a custom extension to the underlying client.
The json function for the extension.
Disable polling features.
Polling feature label.
handshake with the streaming channel
Callback for the handshake when it successfully completes. The handshake should throw errors when errors are encountered.
Sets an http header name/value.
The header name.
The header value.
Subscribes to Comet topics. Subscribe should perform a handshake if one hasn't been performed yet.
The topic to subscribe to.
The callback to execute once a message has been received.
Comet client interface. The is to allow for mocking the inner streaming Cometd implementation. The Faye implementation is used by default but it could be used to adapt another Cometd impl.