Base class for backup request. Workload-specific backup requests are derived from this class.
You probably want to use the sub-classes and not this class directly. Known sub-classes are: AzureFileShareBackupRequest, AzureWorkloadBackupRequest, IaasVMBackupRequest.
All required parameters must be populated in order to send to Azure.
Required. This property will be used as the discriminator for deciding the specific types in the polymorphic chain of types.Constant filled by server.