Takes in a child object, a parent object, and a list of
attribute names. If the child object does not have a non-None
value for an attribute, the value will be inherited from the parent
object.

For further documentation see the following:
https://github.com/HenryGinn/hgutilities
https://github.com/HenryGinn/hgutilities/tree/main/hgutilities/defaults
