In this Unit (MyUnit), this is where all the public functions
that didn't already get implemented are implemented. The functions
that are identical are implemented a level up in the directory
heirarchy. All the implementations sitting at this level are specific
to Impl1. The same files exist for the public functions in
Impl2, but they have implementation specific to Impl2. The
non-public functions may be different between the two (in this case
there is mu_localFoo specific to Impl1, while Impl2 has two local
functions, mu_localFoo1 and mu_localFoo2. Please note that following
the naming convention, the functions have prefixes identifying where
they came from, but are not the same as the public function prefix
"MyUnit". The local prefixes are encouraged but not enforced.