This folder contains a file (`pydrake_sphinx_extension.py`) that uses some code
from Sphinx 1.6.7.

https://github.com/sphinx-doc/sphinx/blob/v1.6.7/sphinx/ext/autodoc.py#L996-L1057

The original license for these files is given in the link below and copied into
file sphinx.LICENSE.txt.

https://github.com/sphinx-doc/sphinx/blob/v1.6.7/LICENSE