--- a/contenttransformer/transformers.py	Wed Jan 13 23:58:13 2010 -0500
+++ b/contenttransformer/transformers.py	Thu Jan 14 00:09:06 2010 -0500
@@ -1,9 +1,11 @@
 import docutils.core
+import subprocess
 from webob import Response
 
 class Graphviz(object):
     def __init__(self, content):
         """create a Graphviz object"""
+        raise NotImplementedError # TODO
 
     def __call__(self, environ, start_response):
         """return a WSGI response"""
@@ -20,4 +22,4 @@
 
     def __call__(self, environ, start_response):
         """return a WSGI response"""
-        return Response(content_type='text/html', body=self.html)
+        return Response(content_type='text/html', body=self.html)(environ, start_response)