== Using Private-Access-Modifier instead of Protected == 

 At work we use the Eclipse platform. Often when I have the wish to implement the same functionality in my plugin, i run into the problem that the available code cannot be reused because a required methods is marked as private. If it were, one could simply overwritten or call it from a subclass. This leads to copy & paste programming. The interessting thing on that is that this is mentioned in the book "Contributing to Eclipse: Principles, Patterns, and Plug-Ins: Principles, Patterns and Plugins (Eclipse Series)" as normal. I suggest to add Eclipse as an example.