code: public Observable<Page<VirtualMachineScaleSetExtensionInner>> listAsync(final String resourceGroupName, final String vmScaleSetName) {
          return listWithServiceResponseAsync(resourceGroupName, vmScaleSetName)
              .map(new Func1<ServiceResponse<Page<VirtualMachineScaleSetExtensionInner>>, Page<VirtualMachineScaleSetExtensionInner>>() {
                  @Override
                  public Page<VirtualMachineScaleSetExtensionInner> call(ServiceResponse<Page<VirtualMachineScaleSetExtensionInner>> response) {
                      return response.body();
                  }
              });
      }
docs: Gets a list of all extensions in a VM scale set.
  
  @param resourceGroupName The name of the resource group.
  @param vmScaleSetName The name of the VM scale set containing the extension.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the observable to the PagedList&lt;VirtualMachineScaleSetExtensionInner&gt; object