code: def set_created_date(self, created_date=None):
          
          if created_date is None:
              raise NullArgument()
          metadata = Metadata(**settings.METADATA['created_date'])
          if metadata.is_read_only():
              raise NoAccess()
          if self._is_valid_input(created_date, metadata, array=False):
              self._my_map['createdDate'] = created_date  # This is probably wrong
          else:
              raise InvalidArgument()
docs: Sets the created date.
  
          :param created_date: the new created date
          :type created_date: ``osid.calendaring.DateTime``
          :raise: ``InvalidArgument`` -- ``created_date`` is invalid
          :raise: ``NoAccess`` -- ``Metadata.isReadOnly()`` is ``true``
          :raise: ``NullArgument`` -- ``created_date`` is ``null``
  
          *compliance: mandatory -- This method must be implemented.*