#!/usr/bin/perl -w
use strict;
use XML::LibXML;

my $parser  = XML::LibXML->new();	
my $doc = $parser->parse_file("model.xml") or die "cannot open xml file: $!";	

my $node = $doc->getDocumentElement();
my @dc = $child[0]->getElementsByTagName('descriptor');	

foreach my $descr (@dc) {
			foreach my $elt ($descr->childNodes())
			 {
				next unless $elt->nodeType() == 1;      #to avoid text nodes                                                 
				$descr->addSibling($elt);
               }
               my $parent = $descr->parentNode;			
               $parent->removeChild($descr);
}

print $child[0]->serialize;