render
Serialize a UDM value to a string in the specified format.
value(required): UDM value to serializeformat(required):"json","xml","yaml","csv"pretty(optional, default false): pretty-print with indentation
utlx
render({name: "Alice"}, "json", true) // pretty-printed JSON
render({Order: {Id: "1"}}, "xml") // "<Order><Id>1</Id></Order>"
// Use case: embed XML inside a JSON field (CDATA pattern)
{
messageId: generateUuid(),
payload: render($input, "xml") // XML as a string value
}