{"ast_node_type":"variable","tokens":[{"end":60,"kind":"keyword","start":0,"text":"let"}]}
    let module_id = db.module_for_file(file_id.file_id(db));
fn eval_main(db: &TestDB, file_id: EditionedFileId) -> Result<(String, String), MirEvalError> {
    let def_map = module_id.def_map(db);