041014 custom. When opening StringBuffer.java from
JDK 1.5's src.zip, the method

public synchronized StringBuffer insert(int
offset, String str) {...}

(for example) is not shown with an override
annotation, even though it clearly overrides a
method in AbstractStringBuilder:

public AbstractStringBuilder insert(int offset,
String str) {...}

(as is evidenced by the use of super.insert in the
body).

On the other hand, Ctrl-B in the body of SB.insert
does jump to ASB.insert!

Cf. also issue #50452 re. Javadoc problems with
this method.