code: def get_simple_topk_program(opset_version=None):
      @mb.program(
          input_specs=[mb.TensorSpec(shape=(1, 1, 4, 4))],
          opset_version=opset_version,
      )
      def prog(x):
          x = mb.topk(x=x, k=1, axis=-1, ascending=True)
          return x
  
      return prog
  
imports: import numpy
  import pytest
  import coremltools
  from coremltools import _logger
  from coremltools.converters.mil.mil import Builder
  from coremltools.converters.mil.mil import Function, Program, types
  from coremltools.converters.mil.mil.passes.tests.test_passes import CONSTEXPR_FUNCS
label_desc: Use image node_id 5 for calling a global function with example usage: get_simple_topk_program(opset_version) and returns: prog, x