Destroys this thread group and all of its subgroups. This thread
group must be empty, indicating that all threads that had been in
this thread group have since stopped.
<p>
First, the {@code checkAccess} method of this thread group is
called with no arguments; this may result in a security exception.
@throws IllegalThreadStateException if the thread group is not
empty or if the thread group has already been destroyed.
@throws SecurityException if the current thread cannot modify this
thread group.
@see java.lang.ThreadGroupEx#checkAccess()
@since 1.0
Destroys this thread group and all of its subgroups. This thread group must be empty, indicating that all threads that had been in this thread group have since stopped. <p> First, the {@code checkAccess} method of this thread group is called with no arguments; this may result in a security exception.
@throws IllegalThreadStateException if the thread group is not empty or if the thread group has already been destroyed. @throws SecurityException if the current thread cannot modify this thread group. @see java.lang.ThreadGroupEx#checkAccess() @since 1.0