code: def test_for_loop_can_read_from_and_write_to_ref_slice(
      self, for_impl
  ):
      def body(i, x_ref):
          x = x_ref[i]
          x_ref[i] = x + jnp.float32(1.0)
  
      x = for_impl(4, body, jnp.ones(4, jnp.float32))
      np.testing.assert_allclose(x, 2 * jnp.ones(4, jnp.float32))
  
      def body2(i, x_ref):
          x = x_ref[i, 0]
          x_ref[i, 1] = x + x_ref[i, 1]
  
      x = for_impl(4, body2, jnp.arange(8.0).reshape((4, 2)))
      np.testing.assert_allclose(
          x,
          jnp.array([[0.0, 1.0], [2.0, 5.0], [4.0, 9.0], [6.0, 13.0]]),
      )
  
imports: from functools import partial
  from absl.testing import absltest
  from absl.testing import parameterized
  import numpy
  import jax
  from jax import random
  from jax._src import test_util
  from jax._src.lax.control_flow import for_loop
  import jax.numpy
  from jax import config
label_desc: Use image node_id 7 for calling the ForLoopTest obj's underlying member method code with example usage: obj.test_for_loop_can_read_from_and_write_to_ref_slice(for_impl) without return types