Un-enterable time unit conversion block

[trexfeathers]

This block:

cf-units/cf_units/__init__.py

Lines 1731 to 1744 in 23bd604

	# Use cftime for converting reference times that are not using a
	# gregorian calendar as it handles these and udunits does not.
	if self.is_time_reference() and self.calendar != CALENDAR_STANDARD:
	result_datetimes = cftime.num2date(
	result, self.cftime_unit, self.calendar
	)
	result = cftime.date2num(
	result_datetimes, other.cftime_unit, other.calendar
	)
	convert_type = isinstance(value, np.ndarray) and np.issubdtype(
	value.dtype, np.floating
	)
	if convert_type:
	result = result.astype(value.dtype)

... will never be entered because it is hidden behind this check:

cf-units/cf_units/__init__.py

Line 1726 in 23bd604

if self.is_convertible(other):

cf-units/cf_units/__init__.py

Lines 998 to 1002 in 23bd604

	else:
	result = self.calendar == other.calendar and _ud.are_convertible(
	self.ut_unit, other.ut_unit
	)
	return result

---

This may be inconsequential given these docs, but in either case this block should presumably be removed?

cf-units/cf_units/__init__.py

Lines 1709 to 1718 in 23bd604

	.. note::
	Conversion between unit calendars is not permitted unless the
	calendars are aliases, see :attr:`cf_units.CALENDAR_ALIASES`.
	>>> from cf_units import Unit
	>>> a = Unit('days since 1850-1-1', calendar='gregorian')
	>>> b = Unit('days since 1851-1-1', calendar='standard')
	>>> a.convert(365.75, b)
	0.75