Hello, please advise why these 2 queries do not work. Samples would be nice.

module namespace foo = "xrpc-test-function";

declare function foo:countQueueStats($docName as xs:string) as xs:integer
{
    count(doc($docName)/qflex:queueStats/qflex:queueStat/qflex:queueName)
};

declare function foo:addQueueStat($docName as xs:string, $myElement as element())
{
    do insert $myElement
    as last into doc($docName)/queueStats
};

Thank you!