write_xml_content($key_file, $source_file_for{$key_file}, $out_fh, ' ' x 4);

##</code><code>##

open my $in_fh, '<', $source_file_for{$key_file};
write_xml_content($key_file, $in_fh, $out_fh, ' ' x 4);
close $in_fh;