{"ast_node_type":"variable","tokens":[{"end":79,"kind":"keyword","start":0,"text":"let"}]}
        let var = self.var_unification_table.new_variable(UniverseIndex::ROOT);
    fn new_var(&mut self, kind: TyVariableKind, diverging: bool) -> Ty {
        // Chalk might have created some type variables for its own purposes that we don't know about...