{"ast_node_type":"function","tokens":[{"end":78,"kind":"keyword","start":0,"text":"fn"}]}
    fn coerce_pin_ref(&self, a: Ty<'tcx>, b: Ty<'tcx>) -> CoerceResult<'tcx> {
    #[instrument(skip(self), level = "trace")]
        debug_assert!(self.shallow_resolve(a) == a);