fix error

Author: Jiayu Liu

datafusion/tests/sql.rs

@@ -802,12 +802,10 @@ async fn csv_query_window_with_empty_over() -> Result<()> {
     let mut ctx = ExecutionContext::new();
     register_aggregate_csv(&mut ctx)?;
     let sql = "SELECT count(c12) over () FROM aggregate_test_100";
-    let actual = execute(&mut ctx, sql).await;
     // FIXME: so far the WindowAggExec is not implemented
-    // and the current behavior is to return empty result
-    // when it is done this test shall be updated
-    let expected: Vec<Vec<String>> = vec![];
-    assert_eq!(expected, actual);
+    // and the current behavior is to throw not implemented exception
+    let plan = ctx.create_logical_plan(&sql);
+    assert!(plan.is_err());
     Ok(())
 }