Returns the handler invoked when this thread abruptly terminates
due to an uncaught exception. If this thread has not had an
uncaught exception handler explicitly set then this thread's
{@code ThreadGroup} object is returned, unless this thread
has terminated, in which case {@code null} is returned.
@return the uncaught exception handler for this thread
Returns the handler invoked when this thread abruptly terminates due to an uncaught exception. If this thread has not had an uncaught exception handler explicitly set then this thread's {@code ThreadGroup} object is returned, unless this thread has terminated, in which case {@code null} is returned. @return the uncaught exception handler for this thread