c_g_dbus_connection_send_message_with_reply

Undocumented in source but is binding to C. You might be able to learn more by searching the web for its name.
__gshared extern (C)
void function(GDBusConnection* connection, GDBusMessage* message, GDBusSendMessageFlags flags, int timeoutMsec, uint* outSerial, GCancellable* cancellable, GAsyncReadyCallback callback, void* userData) c_g_dbus_connection_send_message_with_reply;

Meta