code: def test_ios17_invalid_output_indices_dtype(
      self, compute_unit, backend
  ):
      def build(x):
          return mb.topk(x=x, k=2, axis=1, output_indices_dtype="dummy")
  
      val = np.array([[2, 3, 1], [5, 4, 6]], dtype=np.int32)
      with pytest.raises(
          ValueError, match="invalid output_indices_dtype"
      ):
          run_compare_builder(
              build,
              input_placeholders={
                  "x": mb.placeholder(
                      shape=val.shape, dtype=types.int32
                  )
              },
              input_values={"x": val},
              compute_unit=compute_unit,
              backend=backend,
          )
  
file_path: coremltools/coremltools/converters/mil/mil/ops/tests/iOS17/test_tensor_operation.py
imports: import itertools
  import numpy
  import pytest
  from coremltools.converters.mil.mil import Builder
  from coremltools.converters.mil.mil import types
  from coremltools.converters.mil.mil.ops.tests.iOS17 import backends
  from coremltools.converters.mil.mil.ops.tests.testing_utils import run_compare_builder
  from coremltools.converters.mil.testing_reqs import compute_units
label_desc: Use image node_id 3 for calling the TestTopK obj's underlying member method code with example usage: obj.test_ios17_invalid_output_indices_dtype(compute_unit, backend) and returns: mb