code: public Observable<PreValidateEnableBackupResponseInner> validateAsync(String azureRegion, PreValidateEnableBackupRequest parameters) {
          return validateWithServiceResponseAsync(azureRegion, parameters).map(new Func1<ServiceResponse<PreValidateEnableBackupResponseInner>, PreValidateEnableBackupResponseInner>() {
              @Override
              public PreValidateEnableBackupResponseInner call(ServiceResponse<PreValidateEnableBackupResponseInner> response) {
                  return response.body();
              }
          });
      }
docs: It will validate followings
  1. Vault capacity
  2. VM is already protected
  3. Any VM related configuration passed in properties.
  
  @param azureRegion Azure region to hit Api
  @param parameters Enable backup validation request on Virtual Machine
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the observable to the PreValidateEnableBackupResponseInner object