code: def test_statefullness_single_state_stack(self):
      sequence = np.arange(24).reshape((2, 3, 4)).astype("float32")
      layer = layers.RNN(
          [OneStateRNNCell(3), OneStateRNNCell(2)], stateful=True
      )
      layer(sequence)
      output = layer(sequence)
      self.assertAllClose(
          np.array([[34092.0, 34092.0], [173196.0, 173196.0]]), output
      )
  
file_path: keras/keras/layers/rnn/stacked_rnn_cells_test.py
imports: import numpy
  import pytest
  from keras import layers
  from keras import testing
  from keras.layers.rnn.rnn_test import OneStateRNNCell
  from keras.layers.rnn.rnn_test import TwoStatesRNNCell
label_desc: Use image node_id 4 for calling the StackedRNNTest obj's underlying member method code with example usage: obj.test_statefullness_single_state_stack() without return types