code: public Observable<ServiceResponse<NetworkInterfaceIPConfigurationInner>> getVirtualMachineScaleSetIpConfigurationWithServiceResponseAsync(String resourceGroupName, String virtualMachineScaleSetName, String virtualmachineIndex, String networkInterfaceName, String ipConfigurationName, String expand) {
          if (resourceGroupName == null) {
              throw new IllegalArgumentException("Parameter resourceGroupName is required and cannot be null.");
          }
          if (virtualMachineScaleSetName == null) {
              throw new IllegalArgumentException("Parameter virtualMachineScaleSetName is required and cannot be null.");
          }
          if (virtualmachineIndex == null) {
              throw new IllegalArgumentException("Parameter virtualmachineIndex is required and cannot be null.");
          }
          if (networkInterfaceName == null) {
              throw new IllegalArgumentException("Parameter networkInterfaceName is required and cannot be null.");
          }
          if (ipConfigurationName == null) {
              throw new IllegalArgumentException("Parameter ipConfigurationName is required and cannot be null.");
          }
          if (this.client.subscriptionId() == null) {
              throw new IllegalArgumentException("Parameter this.client.subscriptionId() is required and cannot be null.");
          }
          final String apiVersion = "2017-03-30";
          return service.getVirtualMachineScaleSetIpConfiguration(resourceGroupName, virtualMachineScaleSetName, virtualmachineIndex, networkInterfaceName, ipConfigurationName, this.client.subscriptionId(), apiVersion, expand, this.client.acceptLanguage(), this.client.userAgent())
              .flatMap(new Func1<Response<ResponseBody>, Observable<ServiceResponse<NetworkInterfaceIPConfigurationInner>>>() {
                  @Override
                  public Observable<ServiceResponse<NetworkInterfaceIPConfigurationInner>> call(Response<ResponseBody> response) {
                      try {
                          ServiceResponse<NetworkInterfaceIPConfigurationInner> clientResponse = getVirtualMachineScaleSetIpConfigurationDelegate(response);
                          return Observable.just(clientResponse);
                      } catch (Throwable t) {
                          return Observable.error(t);
                      }
                  }
              });
      }
docs: Get the specified network interface ip configuration in a virtual machine scale set.
  
  @param resourceGroupName The name of the resource group.
  @param virtualMachineScaleSetName The name of the virtual machine scale set.
  @param virtualmachineIndex The virtual machine index.
  @param networkInterfaceName The name of the network interface.
  @param ipConfigurationName The name of the ip configuration.
  @param expand Expands referenced resources.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the observable to the NetworkInterfaceIPConfigurationInner object