[Vala] guess_language warning

[James Campos <james r campos gmail com>]

The guess_language method of a SourceLanguageManager object allows one
null parameter, but when I use it, I get a warning:

james james-desktop:~/code/vala$ valac --pkg gtk+-2.0 --pkg
gtksourceview-2.0 scratch.vala
scratch.vala:9.41-9.44: warning: Argument 2: Cannot pass null to
non-null parameter type
                langManager.guess_language (filepath, null);
                                                      ^^^^
Compilation succeeded - 1 warning(s)
james james-desktop:~/code/vala$ cat scratch.vala
using Gtk;

public class Foo {

        public static int main (string[] args) {

                var filepath = "/home/james/code/vala/scratch.vala";
                var langManager = SourceLanguageManager.get_default ();
                langManager.guess_language (filepath, null);

                return 0;
        }
}


Question: should I continue reporting these strange warnings? Vala
seems to have plenty of them....