code: def test_builder_to_backend_smoke(
      self, compute_unit, backend, is_symbolic
  ):
      x = np.array(
          [
              [1, 2, 3, 4],
              [5, 6, 7, 8],
              [9, 10, 11, 12],
              [13, 14, 15, 16],
          ],
          dtype=np.float32,
      ).reshape(1, 1, 4, 4)
  
      input_shape = list(x.shape)
      placeholder_input_shape = input_shape
      if is_symbolic:
          # set batch and channel dimension symbolic
          placeholder_input_shape[0] = get_new_symbol()
          placeholder_input_shape[1] = get_new_symbol()
  
      input_placeholder_dict = {
          "x": mb.placeholder(shape=placeholder_input_shape)
      }
      input_value_dict = {"x": x}
  
      def build(x):
          return mb.crop(x=x, crop_height=[0, 1], crop_width=[1, 1])
  
      expected_output_type = (
          placeholder_input_shape[0],
          placeholder_input_shape[1],
          3,
          2,
          types.fp32,
      )
      expected_output = np.array(
          [2, 3, 6, 7, 10, 11], dtype=np.float32
      ).reshape(1, 1, 3, 2)
  
      run_compare_builder(
          build,
          input_placeholder_dict,
          input_value_dict,
          expected_output_type,
          expected_output,
          compute_unit=compute_unit,
          backend=backend,
      )
  
imports: import functools
  import itertools
  import numpy
  import pytest
  import coremltools
  from coremltools._deps import _HAS_TORCH, MSG_TORCH_NOT_FOUND
  from coremltools.converters.mil.mil import Builder
  from coremltools.converters.mil.mil import get_new_symbol, types
  from coremltools.converters.mil.mil.ops.tests.iOS14 import backends
  from coremltools.converters.mil.mil.ops.tests.testing_utils import mark_api_breaking, run_compare_builder
  from coremltools.converters.mil.testing_reqs import compute_units
  from coremltools.converters.mil.testing_utils import random_gen
label_desc: Use image node_id 1 for calling the TestCrop obj's underlying member method code with example usage: obj.test_builder_to_backend_smoke(compute_unit, backend, is_symbolic) and returns: mb