func.return
  }
  func.func @empty_func() {
    func.return
  }
}

// -----

// Tests `tf_device.cluster_func` with missing `input_sharding_configuration` attribute.

    attributes, and `func` receives the mhlo.sharding attribute:

    ```mlir
      func @test(%arg0: tensor<*xi32>) {
        %0 = "tf_device.cluster_func"(%arg0) {
            func = @func,
            input_sharding_configuration = ["\01\02\03"],
            output_sharding_configuration = ["\08\01\1A\01\01\22\01\00"],
            step_marker_location = ""} : (tensor<*xi32>) -> tensor<*xi32>
        return
      }