title: Tensorflow TFE_Py_FastPathExecute variable not found in pywrap_tensorflow.py
body: <p>I was reading the source code for <strong>LeakyRelu</strong> in <code>gen_nn_ops.py</code> of <code>tensorflow.python.ops</code> package. The function in there calls <code>_pywrap_tensorflow.TFE_Py_FastPathExecute</code> with eight parameters.</p>
  
  <p>However, <code>TFE_Py_FastPathExecute</code> member doesn't exist in <code>pywrap_tensorflow.py</code>. Where does it refer it from?</p>