A DESCRIPTION OF THE PROBLEM :
According to http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=4143601 setBorder(null) means that the L&F gets to decide what border to use but the internet is full of examples where setBorder(null) is mistaken for "no border". Even Netbeans makes this mistake.

Please document the meaning of setBorder(null).


URL OF FAULTY DOCUMENTATION :
http://download.oracle.com/javase/6/docs/api/javax/swing/JComponent.html#setBorder%28javax.swing.border.Border%29