The specification for java.awt.Container.addImpl(Component comp, Object constraints, int index) method doesn't mention about any NullPointerException(as well as specification for class and package).
But, when I try to invoke this method with comp=null, constraints=null, index=-1, I get NullPointerException. It seems to be out-of-specification.

JCK test fails because of this issue:
api/javax_swing/AbstractButton/index.html#AddImpl[addImpl0009]
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