Update attack ValueError string
@@ -32,9 +32,8 @@ class Attack(object):
" Model class; otherwise the output layer will"
" be inferred by the attack.")
else:
- raise ValueError("model argument must be a function that "
- "returns the symbolic output when given an "
- "input tensor.")
+ raise ValueError("The model argument should be an instance of"
+ " the Model class.")
if back == 'th':
warnings.warn("CleverHans support for Theano is deprecated and "
"will be dropped on 2017-11-08.")
