code: def testSimple(self):
      components = np.random.randint(100, size=(200,)).astype(np.int64)
      dataset = dataset_ops.Dataset.from_tensor_slices(components).map(
          lambda x: x * x
      )
      dataset = dataset.group_by_window(
          key_func=lambda x: x % 2,
          reduce_func=lambda _, xs: xs.batch(4),
          window_size=4,
      )
      get_next = self.getNext(dataset)
      counts = []
      with self.assertRaises(errors.OutOfRangeError):
          while True:
              result = self.evaluate(get_next())
              self.assertTrue(
                  all(x % 2 == 0 for x in result) or all(x % 2 == 1)
                  for x in result
              )
              counts.append(result.shape[0])
  
      self.assertEqual(len(components), sum(counts))
      num_full_batches = len([c for c in counts if c == 4])
      self.assertGreaterEqual(num_full_batches, 24)
      self.assertTrue(all(c == 4 for c in counts[:num_full_batches]))
  
imports: from absl.testing import parameterized
  import numpy
  from tensorflow.core.lib.core import error_codes_pb2
  from tensorflow.python.data.kernel_tests import checkpoint_test_base
  from tensorflow.python.data.kernel_tests import test_base
  from tensorflow.python.data.ops import dataset_ops
  from tensorflow.python.framework import combinations
  from tensorflow.python.framework import constant_op
  from tensorflow.python.framework import dtypes
  from tensorflow.python.framework import errors
  from tensorflow.python.framework import ops
  from tensorflow.python.framework import tensor_shape
  from tensorflow.python.ops import array_ops
  from tensorflow.python.ops import math_ops
  from tensorflow.python.ops import string_ops
  from tensorflow.python.platform import test
label_desc: Use image node_id 6 for calling the GroupByWindowTest obj's underlying member method code with example usage: obj.testSimple() without return types