https://learn.microsoft.com/en-us/dotnet/api/system.servicemodel.operationcontractattribute.isterminating?view=netframework-4.8.1
OperationContractAttribute.IsTerminating Property (System.ServiceModel) | Microsoft Learn
Gets or sets a value that indicates whether the service operation causes the server to close the session after the reply message, if any, is sent.
property systemmicrosoftlearn