Class templates that are declared within the scope of a package should be separated out into individual files with a .svh
extension. These files should be `included in the package in the order in which they need to be compiled. The package
file is the only place where `includes should be used, there should be no further `include statements inside the included
files.
Justification: Having the classes declared in separate files makes them easier to maintain, and it also makes it clearer
what the package content is.