static WebSocketClient of(SessionProtocol protocol, EndpointGroup endpointGroup) {
        return builder(protocol, endpointGroup).build();
    }
Returns a new {@link WebSocketClient} that connects to the specified {@link EndpointGroup} with
the specified {@link SessionProtocol} using the default {@link ClientOptions}.
core/src/main/java/com/linecorp/armeria/client/websocket/WebSocketClient.java