>># 
>># Copyright 1990, 1991 by the Massachusetts Institute of Technology and
>># UniSoft Group Limited.
>># 
>># Permission to use, copy, modify, distribute, and sell this software and
>># its documentation for any purpose is hereby granted without fee,
>># provided that the above copyright notice appear in all copies and that
>># both that copyright notice and this permission notice appear in
>># supporting documentation, and that the names of MIT and UniSoft not be
>># used in advertising or publicity pertaining to distribution of the
>># software without specific, written prior permission.  MIT and UniSoft
>># make no representations about the suitability of this software for any
>># purpose.  It is provided "as is" without express or implied warranty.
>># 
>># $XConsortium: gtslctnown.m,v 1.4 92/06/11 16:13:02 rws Exp $
>># 
>>#      SCCS:  @(#)  EAto.mc Rel 1.6	    (10/4/91)
>>#
>>TITLE XGetSelectionOwner CH04
>>ASSERTION A XGetSelectionOwner-1
A call to XGetSelectionOwner returns the window ID
associated with the window that currently owns the specified
selection.
>>STRATEGY
Create a window with a selection.
Call XGetSelectionOwner to obtain the window ID of the selection owner.
Verify the window ID returned was that of the selection owner.
>>ASSERTION A XGetSelectionOwner-2
When the selection is not owned by a window, then a call to
XGetSelectionOwner returns None.
>>STRATEGY
Ensure the selection has no owner.
Call XGetSelectionOwner to obtain selection owner.
Verify that XGetSelectionOwner returned None.
>>ASSERTION A XGetSelectionOwner-3
When an atom argument does not name a valid Atom, then a
BadAtom error occurs.
>>STRATEGY
Call test function using a value with the top bits set as the atom argument.
Verify that a BadAtom error occurs.
