The proxy server GInetAddress.
The proxy server port.
The proxy protocol to support, in lower case (e.g. socks, http).
The destination hostname the the proxy should tunnel to.
The destination port to tunnel to.
The username to authenticate to the proxy server (or NULL). [allow-none]
The password to authenticate to the proxy server (or NULL). [allow-none]
ConstructionException GTK+ fails to create the object.
Creates a new GProxyAddress for inetaddr with protocol that should tunnel through dest_hostname and dest_port. Since 2.26