A DESCRIPTION OF THE REQUEST :
AssertionError does not have constructors that takes message and a nested throwable. Please add one.

public AssertionError(String message,Throwable cause) { ...}

JUSTIFICATION :
I frequently see code that catches a checked exception that should never be thrown. Sometimes it asserts false, sometimes it throws a RuntimeException, sometimes I'll see an empty catch block, maybe with a comment.

The right thing to do is to throw an AssertionError.

catch(ImpossibleException ie) {
    throw new AssertionError("Flow of control should never throw this exception because blah blah blah.",ie);
}

It's a pretty minor request; AssertionError does have an initCause() method that works fine. Developers rarely take that extra simple step to use initCause(). However, they do use the two-argument constructor in many other places. One was surprised not to find it when I pointed out initCause().

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
I'd like to see a new constructor added to AssertionError. Other developers would use that without blinking.
ACTUAL -
The constructor isn't there, so I use initCause. Other developers are astonished when I suggest it.

CUSTOMER SUBMITTED WORKAROUND :
intiCause() works fine for me. Not for others.