code: def protection_domains(self):
          
          self.connection._check_login()
          response = self.connection._do_get("{}/{}".format(self.connection._api_url, "types/ProtectionDomain/instances")).json()
          all_pds = []
          for pd in response:
              all_pds.append(
                  SIO_Protection_Domain.from_dict(pd)
              )
          return all_pds
docs: :rtype: list of Protection Domains