Nifti1Header.get_xyzt_units is entirely based on the bitfield as it is implemented in nifti1.h. Attempting to generalize it to Minc (#1098) requires reducing the available information, specifically raising a ValueError if the spatial axes have different units.

I think it makes sense to keep this interface which will be mostly useful, but we could start by generalizing, e.g.,

class HasUnits:
 def get_units(self)
 ...

And keep the old behavior:

 def get_xyzt_units(self):
 all_units = self.get_units()
 spatial_units = ...
 temporal_units = ...
 if len(set(spatial_units)) > 1:
 raise ValueError
 if len(set(temporal_units)) > 1:
 raise ValueError
 return spatial_units[0], temporal_units[0]

OTOH, maybe with get_units(), get_xyzt_units() is redundant and can be deprecated.

Thoughts?