{"ast_node_type":"other","tokens":[{"end":58,"kind":"keyword","start":0,"text":"self.probe_const_var(ct_vid).unwrap_err(),"}]}
                self.probe_const_var(ct_vid).unwrap_err(),
            TermVid::Const(ct_vid) => (
                TermVid::Const(self.inner.borrow_mut().const_unification_table().find(ct_vid).vid),