Changes the daemon status of this thread group.
<p>
First, the {@code checkAccess} method of this thread group is
called with no arguments; this may result in a security exception.
<p>
A daemon thread group is automatically destroyed when its last
thread is stopped or its last thread group is destroyed.
@param daemon if {@code true}, marks this thread group as
a daemon thread group; otherwise, marks this
thread group as normal.
@throws SecurityException if the current thread cannot modify
this thread group.
@see java.lang.SecurityException
@see java.lang.ThreadGroupEx#checkAccess()
Changes the daemon status of this thread group. <p> First, the {@code checkAccess} method of this thread group is called with no arguments; this may result in a security exception. <p> A daemon thread group is automatically destroyed when its last thread is stopped or its last thread group is destroyed.
@param daemon if {@code true}, marks this thread group as a daemon thread group; otherwise, marks this thread group as normal. @throws SecurityException if the current thread cannot modify this thread group. @see java.lang.SecurityException @see java.lang.ThreadGroupEx#checkAccess()