code: def test_serializes_boundaries(self):
      vocab_size = 256
      precision = 4
      (_, serializer) = self._make_space_and_serializer(
          low=-1,
          high=1,
          shape=(1,),
          vocab_size=vocab_size,
          precision=precision,
      )
      input_array = np.array([[-1, 1]])
      representation = serializer.serialize(input_array)
      np.testing.assert_array_equal(
          representation,
          [[0] * precision + [vocab_size - 1] * precision],
      )
  
imports: import gin
  import gym
  import numpy
  from tensorflow import test
  from trax.rl import space_serializer
label_desc: Use image node_id 8 for calling the BoxSpaceSerializerTest obj's underlying member method code with example usage: obj.test_serializes_boundaries() without return types