{"ast_node_type":"variable","tokens":[{"end":78,"kind":"keyword","start":0,"text":"if"}]}
                if let ConstScalar::UnevaluatedConst(_, subst) = &c.interned {
            chalk_ir::ConstValue::Concrete(c) => {
                    self.add_constraints_from_invariant_args(subst.as_slice(Interner), variance);