clarification on how to use in-graph

Author: MarkDaoust

samples/core/guide/autograph.ipynb

@@ -172,7 +172,7 @@
       "source": [
         "We'll enable  [eager execution](https://www.tensorflow.org/guide/eager) for demonstration purposes, but AutoGraph works in both eager and [graph execution](https://www.tensorflow.org/guide/graphs) environments:",
         "",
-        "Important: The converted code will _work_ in eager mode. But it runs as an eager-python function. To run the resulting code in a graph use `tf.contrib.eager.defun`."
+        "Important: The converted code will _work_ directly in eager mode. But it runs as an eager-python function. To run in-graph use explicit graphs, as in this doc, or use `tf.contrib.eager.defun`."
       ]
     },
     {