docstr: Tests that encoding works with statically not known input shape.
code: def test_one_to_many_with_unknown_shape(self):
      """Tests that encoding works with statically not known input shape."""
  
      def random_shape_2d_tensor():
          # Returns Tensor of shape [3, <unknown>]
          random_shape_vector = (
              test_utils.get_tensor_with_random_shape()
          )
          return tf.stack([random_shape_vector] * 3)
  
      test_data = self.run_one_to_many_encode_decode(
          self.default_encoding_stage(), random_shape_2d_tensor
      )
      self.common_asserts_for_test_data(test_data)
  
imports: import itertools
  from absl.testing import parameterized
  import numpy
  import tensorflow
  from tensorflow_model_optimization.python.core.internal.tensor_encoding.stages import stages_impl
  from tensorflow_model_optimization.python.core.internal.tensor_encoding.testing import test_utils
label_desc: Use image node_id 5 for calling the FlattenEncodingStageTest obj's underlying member method code with example usage: obj.test_one_to_many_with_unknown_shape() and returns: tf