Prepare languageserver tcp client

example.R

client <- TCPLanguageClient$new(port = 8888) #session 1
    run(port = 8888) # session 2
    client$start()
    data <- client$fetch(blocking = TRUE)
    client$handle_raw(data)
## do stuff with client

    client %>% did_save(defn_file_path2)
    result <- client %>% respond_document_symbol(defn_file_path2)