Trying to increase coverage for some By equivalence methods.  I am not crazy about the naming schemes though.

Trying to increase some unit test coverage for equals methods and hash code methods.
`hashCode` returns a primitive int so it will never be null. Instead, it would be more beneficial to test the contract of `hashCode`, which is that if something is equal to something else, so should their hash codes.

For reference, the `equals` Javadoc says...
> ...maintain the general contract for the hashCode method, which states that equal objects must have equal hash codes.