Fixed grammar for Value Error
Since Tensorflow is the only option the previous sentence was "Backend argument must either be 'tf'.", but that was grammatically incorrect because Tensorflow was the only option, so the I removed the either so the sentence is now "Backend argument must be 'tf'."
@@ -24,7 +24,7 @@ class Attack(object):
:param sess: The tf session to run graphs in
"""
if not(back == 'tf'):
- raise ValueError("Backend argument must either be 'tf'.")
+ raise ValueError("Backend argument must be 'tf'.")
if back == 'tf':
import tensorflow as tf
