Gson codec lost correct type

Hi,

I have a problem with parse xml to json. If I do double referencing on leaf, gson evaluates type of uint32 like string.

input:
<cont xmlns="main:module"
xmlns:cont-augment-module="cont:augment:module">
<cont-augment-module:lf7>200</cont-augment-module:lf7>
</cont>

yang context (for full files see attachments):
module main-module {
namespace "main:module";

prefix "mainmod";
revision 2013-12-2 {
}

container cont {
leaf lf1

{ type uint32; }

}
}

module cont-augment-module {
namespace "cont:augment:module";

prefix "cntaugmod";

import main-module

{prefix mamo; revision-date 2013-12-2;}

revision 2013-12-2 {
}

augment "/mamo:cont" {
leaf lf4 {
type leafref

{ path "../mamo:lf1"; }

}

leaf lf7 {
type leafref

{ path "../lf4"; }

}
}
}