official testing code failed ...

Hello,
Wanting to try geometry-script, I started following the documentation. No problems during installation. No worries either for the first demo code.
On the other hand, here is the error message that I get with the following script...
script
```python
from geometry_script import *

@tree("Cube Tree")
def cube_tree():
return cube(), 5
```
output
```shell
Python: Traceback (most recent call last):
File "/test.py", line 3, in
File "/pathto/.config/blender/4.2/scripts/addons/geometry-script-main/api/tree.py", line 152, in build_tree
result = Type(value=result)
^^^^^^^^^^^^^^^^^^
File "/pathto/.config/blender/4.2/scripts/addons/geometry-script-main/api/types.py", line 57, in __init__
raise Exception(f"'{value}' cannot be expressed as a node.")
Exception: '{'mesh': , 'uv_map': }' cannot be expressed as a node.
```
Could you direct me to the origin of the problem?
I'm taking this opportunity to find out if you plan to maintain the project in the long term (since blender evolves very quickly...), thank you for your feedback

Reproduce the documented Python example in Blender, then inspect api/tree.py and api/types.py around the traceback locations. Determine why the tuple returned by cube_tree() cannot be expressed as a node, and consider the issue complete when the example runs without this exception.

Written by the indexing model from the issue text.