This sample application provides a client for the NIOChatServer. Invoke
it using one of the following syntaxes:
swift run NIOChatClient # Connects to a server on ::1, port 9999.
swift run NIOChatClient 9899 # Connects to a server on ::1, port 9899
swift run NIOChatClient /path/to/unix/socket # Connects to a server using the given UNIX socket
swift run NIOChatClient chat.example.com 9899 # Connects to a server on chat.example.com:9899