code: def observed(self, date_observed=None):
          
          if self.name != 'Indicator':
              self.tcex.log.warning(u'Observed endpoint only available for "indicator" endpoint.')
          else:
              self._request_uri = '{}/observed'.format(self._request_uri)
              if date_observed is not None:
                  self._request.add_payload('dateObserved', date_observed)
docs: Retrieve indicator observations count for top 10