Function same_uid_there 

fn same_uid_there(
    client: &Client,
    kind: Kind,
    listed: &Listed,
    href: &str,
    text: &str,
    refusal: &str,
) -> Result<Option<(String, String, String)>, SyncError>

The item the server holds under the UID of text, a new item it refused at href because another holds that UID (RFC 4791 §5.3.2.1 and RFC 6352 §6.3.2.1, no-uid-conflict, said with 403 or 409; Nextcloud says 400, and a server may say 412): where the refusal names it, else found by a query on the UID (calendar-query, addressbook-query). Its address, ETag and text; None when no other item there holds that UID (a server that answers no query included), and the refusal is what it was.