code: public void trigger(String vaultName, String resourceGroupName, String fabricName, String containerName, String protectedItemName, BackupRequestResource parameters) {
          triggerWithServiceResponseAsync(vaultName, resourceGroupName, fabricName, containerName, protectedItemName, parameters).toBlocking().single().body();
      }
docs: Triggers backup for specified backed up item. This is an asynchronous operation. To know the status of the operation, call GetProtectedItemOperationResult API.
  
  @param vaultName The name of the recovery services vault.
  @param resourceGroupName The name of the resource group where the recovery services vault is present.
  @param fabricName Fabric name associated with the backup item.
  @param containerName Container name associated with the backup item.
  @param protectedItemName Backup item for which backup needs to be triggered.
  @param parameters resource backup request
  @throws IllegalArgumentException thrown if parameters fail the validation
  @throws CloudException thrown if the request is rejected by server
  @throws RuntimeException all other wrapped checked exceptions if the request fails to be sent