Entities returned by Model missing parent methods?

Hello,

I have a series of Models that use corresponding Entities as their $returnTypes. The corresponding Entities all inherit from a BaseEntity class which in turn inherits from CI's Entity class. 

In the course of my unit testing, I'm noticing that when one of my Models returns query results in Entity form, those Entity objects are missing the public methods of their upper-most parent class (the CI Entity). The child methods are not overriding any of the parent's methods. 

If I directly construct an Entity within the Model itself, those inherited methods are there. What am I missing here?

CI version 4.0.4