Andras Deak

Technically we could allow `deep_copy()` to be called with 0 arguments to get a new copy, or a mesh argument for the current behaviour. But 1. type homogeneity would be...

Also pinging @pyvista/developers because the more the merrier and there might be some who don't monitor issues nor slack.

> I don't know whether this is expected or not, but I won't be touching this behavior in this PR. The docs says > This will throw a VTK error/warning...

I also wonder if https://github.com/pyvista/pyvista/issues/137 could be plugged in here. Or at least built on top of this later.

Build failure seems to be due to this flaky silliness again: ``` /home/runner/work/pyvista/pyvista/doc/api/plotting/_autosummary/pyvista.Property.rst: WARNING: document isn't included in any toctree /home/runner/work/pyvista/pyvista/doc/api/plotting/_autosummary/pyvista.plotting.composite_mapper.BlockAttributes.rst: WARNING: document isn't included in any toctree /home/runner/work/pyvista/pyvista/doc/api/plotting/_autosummary/pyvista.plotting.composite_mapper.CompositeAttributes.rst: WARNING:...

I've pushed two minor changes. Probably related to #3168 rather than this PR, but only `__init__` seems to be rendered in doc builds for the new helper classes, e.g. this...

OK, method autodoc is missing even in a full doc build for these three:  I think this needs fixing here.

> PyVista doesn't have many (or any?) `Enum`s. For the record, I added `LightType` at https://github.com/pyvista/pyvista/blob/main/pyvista/plotting/lights.py#L18 via https://github.com/pyvista/pyvista/pull/1040.

Just to plug my `Lights` again, we have the enum https://github.com/pyvista/pyvista/blob/690acb8311b22943090091c4fe2283a5cab2f9bd/pyvista/plotting/lights.py#L18-L23 But then its values are pulled into the `Lights` class namespace: https://github.com/pyvista/pyvista/blob/690acb8311b22943090091c4fe2283a5cab2f9bd/pyvista/plotting/lights.py#L122-L125 It would obviously be messier with a...

Perhaps deprecate this too if we touch this: https://github.com/pyvista/pyvista/blob/e79c03369dcaf57292ae6b7b366410d82debcee7/pyvista/core/composite.py#L434-L443 If we treat the MultiBlock as an iterator then it should just rely on `next(multi)` rather than exposing a `multi.next()` that's...