Use unittest framework in the Automated Installer Testing Framework.

chrome/test/mini_installer/verifier.py

 # Copyright 2013 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import registry_verifier
 
+
 def Verify(property):
-  """Verifies that the current machine states match the property object."""
+  """Verifies that the current machine states match the property dictionary.
+
+  A property dictionary is a dictionary where each key is a verifier's name and
+  the associated value is the input to that verifier. For details about the
+  input format for each verifier, take a look at http://goo.gl/1P85WL
+
+  Args:
+    property: A property dictionary.
+  """
   for verifier_name, value in property.iteritems():
     if verifier_name == 'RegistryEntries':
       registry_verifier.VerifyRegistryEntries(value)
     else:
       # TODO(sukolsak): Implement other verifiers
-      # TODO(sukolsak): Use unittest framework instead of exceptions.
-      raise Exception('Unknown verifier')
+      raise KeyError('Unknown verifier %s' % verifier_name)