Call this function to obtain the array of proxy URIs when g_proxy_resolver_lookup_async() is complete. See g_proxy_resolver_lookup() for more details.

Looks into the system proxy configuration to determine what proxy, if any, to use to connect to @uri. The returned proxy URIs are of the form `<protocol>://user[:password]@host:port` or `direct://`, where <protocol> could be http, rtsp, socks or other proxying protocol.

If you don't know what network protocol is being used on the socket, you should use `none` as the URI protocol. In this case, the resolver might still return a generic proxy type (such as SOCKS), but would not return protocol-specific proxy types (such as http).

`direct://` is used when no proxy is needed. Direct connection should not be attempted unless it is part of the returned array of proxies.

Checks if @resolver can be used on this system. (This is used internally; g_proxy_resolver_get_default() will only return a proxy resolver that returns %TRUE for this method.)