code: def set_published(self, published=None):
          
          if published is None:
              raise NullArgument()
          metadata = Metadata(**settings.METADATA['published'])
          if metadata.is_read_only():
              raise NoAccess()
          if self._is_valid_input(published, metadata, array=False):
              self._my_map['published'] = published
          else:
              raise InvalidArgument()
docs: Sets the published status.
  
          :param published: the published status
          :type published: ``boolean``
          :raise: ``NoAccess`` -- ``Metadata.isReadOnly()`` is ``true``
  
          *compliance: mandatory -- This method must be implemented.*