Replacing custom providers documentation example with literalinclude

docs/providers/custom.rst

@@ -30,44 +30,5 @@ Example:
     :width: 100%
     :align: center
 
-.. code-block:: python
-
-    """Custom `Factory` example."""
-
-    from objects.providers import Provider
-    from objects.providers import Factory
-
-
-    class User(object):
-
-        """Example class User."""
-
-
-    class UsersFactory(Provider):
-
-        """Example users factory."""
-
-        __slots__ = ('_factory',)
-
-        def __init__(self):
-            """Initializer."""
-            self._factory = Factory(User)
-            super(UsersFactory, self).__init__()
-
-        def _provide(self, *args, **kwargs):
-            """Return provided instance."""
-            return self._factory(*args, **kwargs)
-
-
-    # Users factory:
-    users_factory = UsersFactory()
-
-    # Creating several User objects:
-    user1 = users_factory()
-    user2 = users_factory()
-
-    # Making some asserts:
-    assert isinstance(user1, User)
-    assert isinstance(user2, User)
-    assert user1 is not user2
-
+.. literalinclude:: ../../examples/providers/custom_factory.py
+   :language: python