For example, suppose package physics contains a Math class that’s identical to java.lang ‘s Math class in that it implements the same PI constant and trigonometric methods.

The Javadoc documentation for the Package class states: Package objects contain version information about the implementation and specification of a Java package. This versioning information is ...

While there are workarounds -- for example, you could introduce a Factory class to generate transaction objects -- this adds complexity and could become a maintenance burden. Another approach could be ...