Add parameter to open nodes of DocumentTree to given level/depth

I'm a bit puzzled by the name of the parameter, regarding to what it's supposed to do. Sebastian I have the feeling by reading the description that this parameter wouldn't have any impact on what's displayed by the actual openTo parameter, could you confirm that it's what you have in mind?
To give an example, if we consider that {{documentTree openTo="document:xwiki:Sandbox.WebHome" /}} would display:

- Help
- Bar
- Foo
- Sandbox
   - Sandbox Test Page 1
   - Sandbox Test Page 2
   - Sandbox Sub Space

Then do you confirm that {{documentTree openTo="document:xwiki:Sandbox.WebHome" openToLevel="1" /}} would diplay:

- Help
   - Help Page 1
- Bar
   - Sub Bar
- Foo
   - My Foo
- Sandbox
   - Sandbox Test Page 1
   - Sandbox Test Page 2
   - Sandbox Sub Space

And not:

- Help
- Bar
- Foo
- Sandbox
   - Sandbox Test Page 1
   - Sandbox Test Page 2
   - Sandbox Sub Space
      - Sub sandbox