New Methods for MirrorCell
Whenever we instantiate cells from the MirrorCell we need to take an extra step of orienting the mirror. As a practical matter, the MirrorCell must always have one orientation, left or right. We can streamline this behavior with a few new class methods on MirrorCell. Note we are using a new class methods protocol of "instance creation".
We can go back and incorporate these new methods in our unit tests -- in a few places only so that the old technique is still tested too.
After we make these changes we should once again run our unit tests and validate our changes.