code: def remove_tls_credential(self, credentials):
          
          for cred in credentials:
              href = element_resolver(cred)
              if href in self.engine.server_credential:
                  self.engine.server_credential.remove(href)
docs: Remove a list of TLSServerCredentials on this engine.
          
          :param credentials: list of credentials to remove from the
              engine
          :type credentials: list(str,TLSServerCredential)
          :return: None