code: def test_significance_map(self):
      (_, serializer) = self._make_space_and_serializer(shape=(2,))
      np.testing.assert_array_equal(
          serializer.significance_map, [0, 1, 2, 3, 0, 1, 2, 3]
      )
  
imports: import gin
  import gym
  import numpy
  from tensorflow import test
  from trax.rl import space_serializer
label_desc: Use image node_id 7 for calling the BoxSpaceSerializerTest obj's underlying member method code with example usage: obj.test_significance_map() without return types