docs: def _send_solr_command(self, core_url, json_command):
          """
          Sends JSON string to Solr instance
          """
  
          # Check document language and dispatch to correct core
          url = _get_url(core_url, "update")
          try:
              response = self.req_session.post(url, data=json_command, headers={'Content-Type': 'application/json'})
              response.raise_for_status()
          except requests.RequestException as e:
              logger.error("Failed to send update to Solr endpoint [%s]: %s", core_url, e, exc_info=True)
              raise SolrException("Failed to send command to Solr [%s]: %s" % (core_url, e,))
          return True