message: Fix a piece of lint in the docstring for `tf_export` (non-matching quote characters).
diff: @@ -34,7 +34,7 @@ tf_export('foo', 'bar.foo')(foo)
  Exporting a constant
  ```python
  foo = 1
  -tf_export("consts.foo").export_constant(__name__, 'foo')
  +tf_export('consts.foo').export_constant(__name__, 'foo')
  ```
  """
  from __future__ import absolute_import
  