use Carp;

sub example {
    my %options = (
        'DEBUG'     =>  0,
        'TMPL_PATH' =>  undef
    );
    my %args = ( %options, @_ );
    foreach ( keys %args ) {
        croak( 'Unknown argument passed to subroutine - ', $_ )
            unless exists $options{$_};
    }

    .
    .

}