docs: def clear_start_date(self):
          """Clears the start date.
  
          raise:  NoAccess - ``Metadata.isRequired()`` or
                  ``Metadata.isReadOnly()`` is ``true``
          *compliance: mandatory -- This method must be implemented.*
  
          """
          if (self.get_start_date_metadata().is_read_only() or
                  self.get_start_date_metadata().is_required()):
              raise errors.NoAccess()
          self._my_map['startDate'] = self._mdata['start_date']['default_date_time_values'][0]