def _assert_no_rewrite(self, control_ir, test_ir):
        """
        Given two dictionaries of Numba IR blocks, check to make sure
        the control IR and the test IR both have no array expressions.
        """
        self.assertEqual(len(control_ir), len(test_ir))
        # All blocks should be identical, and not rewritten
        for k, v in control_ir.items():
            control_block = v.body
            test_block = test_ir[k].body
            self.assertEqual(len(control_block), len(test_block))
            self._assert_array_exprs(control_block, 0)
            self._assert_array_exprs(test_block, 0)

        Given two dictionaries of Numba IR blocks, check to make sure
        the control IR and the test IR both have no array expressions.
        
numba/tests/test_array_exprs.py