if ( defined &test_sub ) {
    test_sub();
} else {
    print "Subroutine doesn't exist";
}


##</code><code>##

if ( defined &$TEST->test_sub ) {
    TEST->test_sub;
} else {
    print "Method doesn't exist";
}


##</code><code>##

Not a CODE reference at (eval 22)[/opt/perl/5.8.0/lib/perl5db.pl:17] line 2, <STDIN> line 3.