>># 
>># 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: stwdwbg.m,v 1.6 92/06/11 16:10:32 rws Exp $
>># 
>>#      SCCS:  @(#)  EMat4.mc Rel 1.3	    (7/19/91)
>>#      SCCS:  @(#)  EWin.mc Rel 1.4	    (7/19/91)
>>#
>>TITLE XSetWindowBackground CH03
>>ASSERTION A XSetWindowBackground-1
A call to XSetWindowBackground sets the background of the
window to the pixel value specified by background_pixel.
>>STRATEGY
Create a window.
Set the background_pixel by calling XSetWindowBackground.
Verify the background pixel was set to background_pixel using XGetPixel.
>>ASSERTION A XSetWindowBackground-2
When the background is changed, then the window contents
are not changed.
>>STRATEGY
Create a window.
Set the background-pixmap
Map window over a plain background.
Change background pixel. 
Verify that background has not changed.
>>ASSERTION A XSetWindowBackground-3
When the window argument is an InputOnly window then a
BadMatch error occurs.
>>STRATEGY
Create an InputOnly window.
Call test function using InputOnly window as the window argument.
Verify that a BadMatch error occurs.
>>ASSERTION A XSetWindowBackground-4
When a window argument does not name a valid Window, then a
BadWindow error occurs.
>>STRATEGY
Create a bad window by creating and destroying a window.
Call test function using bad window as the window argument.
Verify that a BadWindow error occurs.
