{"ast_node_type":"variable","tokens":[{"end":61,"kind":"keyword","start":0,"text":"let"}]}
    let (db, file_id) = TestDB::with_single_file(ra_fixture);
fn check(#[rust_analyzer::rust_fixture] ra_fixture: &str, expect: Expect) {
    let item_tree = db.file_item_tree(file_id.into());