>># 
>># 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: lstdpths.m,v 1.5 92/06/11 16:00:03 rws Exp $
>># 
>>#
>>TITLE XListDepths CH02
>>ASSERTION B XListDepths-1
A call to XListDepths returns an array which can be freed
with XFree, of all depths which are available on the screen
screen_number and whose size is returned through the
count_return argument.
>>STRATEGY
Obtain the list of supported depths using XListDepths.
For each number in the list:
  Create a pixmap of that depth.
  Verify that no error occurred.
For numbers not in the list of depths:
  Create a pixmap of the depth.
  Verify that it was not successful.
Free the list using XFree.
>>ASSERTION A XListDepths-2
When screen_number is not a valid screen, then a call to
XListDepths does not set the count_return argument and
returns NULL.
>>STRATEGY
List the depths of an invalid screen using XListDepths.
Verify that the function returns NULL.
Verify that the count_return argument was unchanged.
>>ASSERTION B XListDepths-3
When sufficient memory cannot be allocated for the returned
array, then a call to XListDepths does not set the
count_return argument and returns NULL.
>>STRATEGY
Report UNTESTED
