@abc.abstractmethod<EOL><INDENT>def set_published_date(self, published_date):<DEDENT>
pass<EOL>
Sets the published date.

        :param published_date: the new published date
        :type published_date: ``osid.calendaring.DateTime``
        :raise: ``InvalidArgument`` -- ``published_date`` is invalid
        :raise: ``NoAccess`` -- ``Metadata.isReadOnly()`` is ``true``
        :raise: ``NullArgument`` -- ``published_date`` is ``null``

        *compliance: mandatory -- This method must be implemented.*