use strict;
use XML::Simple;

my $xml_src  = 
'<foo>
  <bar><number>1</number><foobar>Hello world</foobar><barfoo>Goodbye world</barfoo></bar>
  <bar><number>2</number><foobar>abc</foobar><barfoo>def</barfoo></bar>
</foo>'
;

my $xml_in = XMLin($xml_src, );
my $xml_out = XMLout(Test(), rootname=>'foo');

# how do I make $xml_out == $xml_src ?
print "Source:\n" . $xml_src . "\n\n";
print "Output:\n" . $xml_out . "\n";

sub Test{
  my $entry;
  my $out;
  foreach $entry(@{${$xml_in}{'bar'}}){
    push @{${$out}{'bar'}}, $entry;
  }
  return $out;
}