-from numbers import Number
-from typing import Callable
+"""Utilities involving converting between different units."""
+
+from typing import Callable, SupportsFloat
src = conversion_catalog.get(from_thing, None)
dst = conversion_catalog.get(to_thing, None)
if src is None or dst is None:
src = conversion_catalog.get(from_thing, None)
dst = conversion_catalog.get(to_thing, None)
if src is None or dst is None: