Update test.

Author: dgercho

tests/test_tree.py

@@ -723,9 +723,14 @@ def test_shallow_paste(self):
         n3 = t3.create_node(identifier="C")
 
         t1.paste(n1.identifier, t2)
-        self.assertEqual(t1.to_dict(), {"A": {"children": ["B"]}})
+        self.assertEqual(
+            t1.to_dict(), {"A": {"id": "A", "children": [{"B": {"id": "B"}}]}}
+        )
         t1.paste(n1.identifier, t3)
-        self.assertEqual(t1.to_dict(), {"A": {"children": ["B", "C"]}})
+        self.assertEqual(
+            t1.to_dict(),
+            {"A": {"id": "A", "children": [{"B": {"id": "B"}}, {"C": {"id": "C"}}]}},
+        )
 
         self.assertEqual(t1.level(n1.identifier), 0)
         self.assertEqual(t1.level(n2.identifier), 1)