code: def ecp_endpoint(self, ipaddress):
          
          _ecp = self.getattr("ecp")
          if _ecp:
              for key, eid in _ecp.items():
                  if re.match(key, ipaddress):
                      return eid
  
          return None
docs: Returns the entity ID of the IdP which the ECP client should talk to
  
          :param ipaddress: The IP address of the user client
          :return: IdP entity ID or None