Wraps base_io_stream and socket together as a #GSocketConnection.
Gets conn's base #GIOStream
Checks if graceful disconnects are used. See gio.tcp_connection.TcpConnection.setGracefulDisconnect.
This enables graceful disconnects on close. A graceful disconnect means that we signal the receiving end that the connection is terminated and wait for it to close the connection before closing the connection.
A gio.tcp_wrapper_connection.TcpWrapperConnection can be used to wrap a gio.iostream.IOStream that is based on a gio.socket.Socket, but which is not actually a gio.socket_connection.SocketConnection. This is used by gio.socket_client.SocketClient so that it can always return a gio.socket_connection.SocketConnection, even when the connection it has actually created is not directly a gio.socket_connection.SocketConnection.