OptionaloncloseCallback for when the connection is closed for any reason.
This should be invoked when close() is called as well.
OptionalonerrorCallback for when an error occurs.
Note that errors are not necessarily fatal; they are used for reporting any kind of exceptional condition out of band.
OptionalonmessageCallback for when a message (request or response) is received over the connection.
Includes the requestInfo and authInfo if the transport is authenticated.
The requestInfo can be used to get the original request information (headers, etc.)
Closes the connection.
Sends a JSON-RPC message (request or response).
If present, relatedRequestId is used to indicate to the transport which incoming request to associate this outgoing message with.
Starts processing messages on the transport, including any connection steps that might need to be taken.
This method should only be called after callbacks are installed, or else messages may be lost.
NOTE: This method should not be called explicitly when using Client, Server, or Protocol classes, as they will implicitly call start().
Client transport for WebSocket: this will connect to a server over the WebSocket protocol.