comparing positive and negative angles in `degrees_east`

[dcherian]

from cf_xarray.units import units

220 * units.degrees_east == (-140 * units.degrees_east)

is False. Can this be True instead?

[jthielen]

This would be a good thing to ask upstream in Pint! I'm not aware of any modular arithmetic support, but I definitely see something like this being useful.