code: def testExtendOpErrorNotList(self):
      # Should be a list.
      values = StructuredTensor.from_pyval({})
  
      def leaf_op(values):
          return values[0]
  
      with self.assertRaisesRegex(ValueError, "Expected a list"):
          structured_array_ops._extend_op(values, leaf_op)
  
imports: from absl.testing import parameterized
  from tensorflow.python.eager import def_function
  from tensorflow.python.framework import dtypes
  from tensorflow.python.framework import random_seed
  from tensorflow.python.framework import tensor
  from tensorflow.python.framework import tensor_shape
  from tensorflow.python.framework import test_util
  from tensorflow.python.ops import array_ops
  from tensorflow.python.ops import math_ops
  from tensorflow.python.ops import random_ops
  from tensorflow.python.ops.ragged import ragged_factory_ops
  from tensorflow.python.ops.ragged import ragged_tensor
  from tensorflow.python.ops.ragged import row_partition
  from tensorflow.python.ops.ragged.dynamic_ragged_shape import DynamicRaggedShape
  from tensorflow.python.ops.structured import structured_array_ops
  from tensorflow.python.ops.structured import structured_tensor
  from tensorflow.python.ops.structured.structured_tensor import StructuredTensor
  from tensorflow.python.platform import googletest
  from tensorflow.python.util import nest
label_desc: Use image node_id 23 for calling the StructuredArrayOpsTest obj's underlying member method code with example usage: obj.testExtendOpErrorNotList() and returns: values