cfunction (net/shutdown stream &opt mode) Stop communication on this socket in a graceful manner, either in both directions or just reading/writing from the stream. The `mode` parameter controls which communication to stop on the socket. * `:wr` is the default and prevents both reading new data from the socket and writing new data to the socket. * `:r` disables reading new data from the socket. * `:w` disable writing data to the socket. Returns the original socket.