{"ast_node_type":"function","tokens":[{"end":57,"kind":"keyword","start":0,"text":"pub(crate)"}]}
    pub(crate) fn new(ecx: &'a mut ExtCtxt<'b>) -> Self {
impl<'a, 'b> Rustc<'a, 'b> {
        let expn_data = ecx.current_expansion.id.expn_data();