code: def test_identity_vector(self):
      identity = self.variant(transforms.identity)
      # Test output.
      np.testing.assert_allclose(identity(self.xs), self.xs)
  
imports: import functools
  from absl.testing import absltest
  from absl.testing import parameterized
  import chex
  import jax
  import jax.numpy
  import numpy
  from rlax._src import transforms
label_desc: Use image node_id 3 for calling the TransformsTest obj's underlying member method code with example usage: obj.test_identity_vector() without return types