code: def test_none_arg(self):
      f = jnp.vectorize(lambda x, y: x if y is None else x + y)
      x = jnp.arange(10)
      self.assertAllClose(f(x, None), x)
  
      y = jnp.arange(10, 20)
      self.assertAllClose(f(x, y), x + y)
  
imports: from functools import partial
  from absl.testing import absltest
  import numpy
  import jax
  from jax import numpy
  from jax._src import test_util
  from jax import config
label_desc: Use image node_id 18 for calling the VectorizeTest obj's underlying member method code with example usage: obj.test_none_arg() without return types