Constructs a new instance of this class. This is equivalent
to calling <code>Shell((Display) null)</code>.
@exception SWTException <ul>
<li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the parent</li>
<li>ERROR_INVALID_SUBCLASS - if this class is not an allowed subclass</li>
</ul>
Constructs a new instance of this class. This is equivalent to calling <code>Shell((Display) null)</code>.
@exception SWTException <ul> <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the parent</li> <li>ERROR_INVALID_SUBCLASS - if this class is not an allowed subclass</li> </ul>