code: def test_flatten_with_dynamic_dimension(self):
      input_layer = layers.Input(batch_shape=(5, 2, None))
      flattened = layers.Flatten()(input_layer)
      self.assertEqual(flattened.shape, (5, None))
  
file_path: keras/keras/layers/reshaping/flatten_test.py
imports: import numpy
  import pytest
  from absl.testing import parameterized
  from keras import backend
  from keras import layers
  from keras import ops
  from keras import testing
label_desc: Use image node_id 4 for calling the FlattenTest obj's underlying member method code with example usage: obj.test_flatten_with_dynamic_dimension() without return types