def database_names(self, session=None):
        """**DEPRECATED**: Get a list of the names of all databases on the
        connected server.

        :Parameters:
          - `session` (optional): a
            :class:`~pymongo.client_session.ClientSession`.

        .. versionchanged:: 3.7
           Deprecated. Use :meth:`list_database_names` instead.

        .. versionchanged:: 3.6
           Added ``session`` parameter.
        """
        warnings.warn("database_names is deprecated. Use list_database_names "
                      "instead.", DeprecationWarning, stacklevel=2)
        return self.list_database_names(session)