Yes, it applies to your situation. I couldn't install X11::GUITest, so I created a dummy package to illustrate the technique.

The package 'Bogus' in my example is analogous to X11::GUITest in your example i.e. it contains the subs that you want to wrap.

So translating to your example it would look like:

package X11_GUITest_Wrapper;
use Moose;
use MooseX::NonMoose;
extends 'X11::GUITest';

around [qw( SendKeys FindWindowLike ClickWindow SetEventSendDelay )] =
+> sub {
    my $orig = shift;
    my $self = shift;
    $orig->(@_);
};

1;
[download]

Then to use it:

package FFMech;

$ENV{'DISPLAY'} = ':0.0';
use Moose;
use Modern::Perl;
use MooseX::NonMoose;
extends 'WWW::Mechanize::Firefox';

has 'x11_guitest_wrapper' => (
    is => 'bare',
    default => sub { X11_GUITest_Wrapper->new },
    handles => [qw( SendKeys FindWindowLike ClickWindow SetEventSendDe
+lay )],
);

# ...

1;
[download]