Added another test for menu_tree.

src/test.rs

@@ -174,3 +174,15 @@ fn test_menu_complex() {
   assert_eq!(a_menu_tree, b)
 }
 
+#[test]
+fn test_menu_cascading() {
+  let (_, a) = parser::tree("([1.0]A[0.5]([1.0]B[2.5]([1.3]C[1.4]D)))").unwrap();
+  let (_, b) = parser::tree("([1.0]A[4.4]D)").unwrap();
+  let Some((a_menu_tree, _)) = a.menu_tree(&[
+    "A".to_owned(), "D".to_owned()
+      ]) else {
+    panic!("Failed to get tree from menu_tree output")
+  };
+  assert_eq!(a_menu_tree, b)
+}
+