Duplicate ?xml when rendering the document

Hi!

I'm testing it now using this page: https://naturalintelligence.github.io/fast-xml-parser/

I noticed that if I provide XML like this:

<?xml version="1.0" encoding="utf-8"?>
<test></test>

it generates me the JSON like this:

{
    "?xml": {
        "@_version": "1.0",
        "@_encoding": "utf-8"
    },
    "test": ""
}

now when I render XML again I have ?xml node described twice:

<?xml version="1.0"?>
<?xml version="1.0" encoding="utf-8"?>
<test></test>

and if I parse such XML of course it fails.

Could you please check why? Is it a bug of the library or just the UI issue? Thanks!

Start with the reproduction on the fast-xml-parser demo page and use the XML and JSON examples in the report to trace the parse-then-render flow. Verify whether the XML declaration is added both from configuration and from the parsed "?xml" node. Done means rendering the reported input produces one declaration and the result can be parsed again.