Returns the RequestHandler/NotificationHandler/ResponseHandler corresponding to a specific LSP method.
Checks if a method has a response handler registered for it. Used to determine if the server should send a request or a notification to the client (if the method has a response handler, then the server will expect a response and thus send a request instead of a notification).
Registers a new handler of any kind (RequestHandler, NotificationHandler or ResponseHandler).
Registers a new dynamic ResponseHandler (used at runtime)