pub fn item(&mut self, item_name: impl Into<T>) -> &mut Self
    where
        T: Hash + Eq,
    {
        self.current_span.cts.entry(item_name.into()).and_modify(|x| *x += 1).or_insert(1);
        self
    }
Add an item to this span.
crates/core/machine/src/utils/span.rs