It was "doctest.module attribute". Now it is "module attribute".
The module docstring, and all function, class and method docstrings are
searched. Objects imported into the module are not searched.
+.. currentmodule:: None
+
.. attribute:: module.__test__
:no-typesetting:
+.. currentmodule:: doctest
+
In addition, there are cases when you want tests to be part of a module but not part
of the help text, which requires that the tests not be included in the docstring.
Doctest looks for a module-level variable called ``__test__`` and uses it to locate other