{"ast_node_type":"other","tokens":[{"end":60,"kind":"keyword","start":0,"text":"chalk_ir::VariableKind::Ty(_ty_kind)"}]}
        chalk_ir::VariableKind::Ty(_ty_kind) => find_var(iv)
    let fallback = |iv, kind, default, binder| match kind {
            .map_or(default, |i| BoundVar::new(binder, i).to_ty(Interner).cast(Interner)),