API Mistake Found -> .to_preferred()

[gaokeyan123]

if you run this,

a = 0 * UReg.kilogram / UReg.meter ** 3 / UReg.second
print(a.to_preferred([UReg.hour]))

it gives error:

pint.errors.DimensionalityError: Cannot convert from 'kilogram / meter ** 3 / second' ([mass] / [length] ** 3 / [time]) to 'kilogram ** 1 / hour / meter ** 3' ([mass] ** 1 / [time] / [length] ** 3)

[andrewgsavage]

you also need to provide a mass and distance unit

we could change it so the units in the original quantity are used when there aren't any units of a dimension

e: ah maybe I've misunderstood this as it looks like it tried to do what I suggested. is it beacuse it's a 0 magnitude quantity?