The javadoc comments for all of BatchUpdateException's constructors that don't take a cause argument, say that initCause() can be called to initialize the cause:

> The cause is not initialized, and may subsequently be initialized by a call
> to the Throwable.initCause(java.lang.Throwable) method.

As of b142, this is no longer true (also tested b143 and b144). For example, the following code

        BatchUpdateException bue = new BatchUpdateException();
        bue.initCause(new Throwable());

results in this exception being thrown:

Exception in thread "main" java.lang.IllegalStateException: Can't overwrite cause
at java.lang.Throwable.initCause(Throwable.java:456)
at BUE.main(BUE.java:6)