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Articles flash: subclassing builders, method/class/package sizes

A quickie:

When you have a class with a builder, and you want to subclass that class, you also want to subclass the builder. But things get nasty quickly, as your subtypes' builder doesn't work nicely.
A good solution from Stackoverflow:
http://stackoverflow.com/questions/17164375/subclassing-a-java-builder-class

Also, a thingie on sizes. When is a class too big, when is a method too big, when is a package kinda big:
https://www.javacodegeeks.com/2012/12/rule-of-30-when-is-a-method-class-or-subsystem-too-big.html

Although I don't agree on the rule of thirty (I think it's too big. Maybe 30/10/10 is more appropriate), it's a good start, and has some nice references.
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