{"ast_node_type":"function","tokens":[{"end":59,"kind":"keyword","start":0,"text":"pub(crate)"}]}
    pub(crate) fn synthesize_region_name(&self) -> Symbol {
    /// This is _not_ idempotent. Call `give_region_a_name` when possible.
        let c = self.next_region_name.replace_with(|counter| *counter + 1);