code: def test_op_minus(left_operand, right_operand, device_id, precision):
      expected_forward = AA(
          [left_operand], dtype=PRECISION_TO_TYPE[precision]
      ) - AA([right_operand], dtype=PRECISION_TO_TYPE[precision])
  
      expected_backward = {
          "left_arg": [
              [
                  np.ones_like(x, dtype=PRECISION_TO_TYPE[precision])
                  for x in left_operand
              ]
          ],
          "right_arg": [
              [
                  -1
                  * np.ones_like(x, dtype=PRECISION_TO_TYPE[precision])
                  for x in right_operand
              ]
          ],
      }
      from .. import minus
  
      _test_binary_op(
          precision,
          device_id,
          minus,
          left_operand,
          right_operand,
          expected_forward,
          expected_backward,
      )
  
      _test_binary_op(
          precision,
          device_id,
          "-",
          left_operand,
          right_operand,
          expected_forward,
          expected_backward,
      )
  
imports: from __future__ import division
  import numpy
  import pytest
  import cntk
  from .ops_test_utils import unittest_helper, _test_unary_op, _test_binary_op, AA, precision, PRECISION_TO_TYPE, cntk_device
  from cntk.internal import sanitize_dtype_cntk
  from cntk.internal.utils import _ones_like, eval
label_desc: Use image node_id 5 for calling a global function with example usage: test_op_minus(left_operand, right_operand, device_id, precision) without return types