package Nose;

use XML::LibXML;
use Moo::Role;

my $xml = sub {
    my ( $self, $params ) = @_; # you really need $self
    my $doc   = XML::LibXML::Document->new( '1.0', 'utf-8' );
    my $root  = $doc->createElement("myapp");
    my $tag   = $doc->createElement("nose");
    my $value = $params->{"nose"};
    $tag->appendTextNode($value);
    $root->appendChild($tag);
    $doc->setDocumentElement($root);
    $doc->toString();
};

sub nose {
    my ( $self, $params ) = @_;
    $self->$xml($params);
}

1;

__END__