code: def test_builder_to_backend_smoke(self, compute_unit, backend):
      x_val = np.array(
          [[-4.7182, 11.94], [-3.3939, 9.2166]], dtype=np.float32
      )
      weight_val = np.array(
          [[1.2313, -0.095], [-1.4075, -0.8816]], dtype=np.float32
      )
      bias_val = np.array([1.0, 2.0], dtype=np.float32)
      input_placeholders = {"x": mb.placeholder(shape=x_val.shape)}
      input_values = {"x": x_val}
  
      def build(x):
          return [mb.linear(x=x, weight=weight_val, bias=bias_val)]
  
      expected_output_types = [(2, 2, types.fp32)]
      expected_outputs = [
          np.array(
              [[-5.9438195, -1.8854373], [-4.054486, -1.3484411]],
              dtype=np.float32,
          )
      ]
  
      run_compare_builder(
          build,
          input_placeholders,
          input_values,
          expected_output_types,
          expected_outputs,
          compute_unit=compute_unit,
          backend=backend,
      )
  
imports: import itertools
  import platform
  import numpy
  import pytest
  import coremltools
  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 run_compare_builder
  from coremltools.converters.mil.mil.types import builtin_to_string, nptype_from_builtin
  from coremltools.converters.mil.testing_reqs import compute_units
  from coremltools.converters.mil.testing_utils import random_gen, ssa_fn
label_desc: Use image node_id 1 for calling the TestLinear obj's underlying member method code with example usage: obj.test_builder_to_backend_smoke(compute_unit, backend) and returns: list