code: def test_filter_custom_vjp_defvjp():
      @eqx.filter_custom_vjp
      def f(x):
          a, b = x
          return (a + 1, b + 2, b + 3)
  
      def f_fwd(x):
          return f(x), None
  
      def f_bwd(res, g, x):
          g0, g1, g2 = g
          return g0 + g1, g2
  
      with pytest.warns():
          f.defvjp(f_fwd, f_bwd)
      jax.grad(lambda x: sum(f(x)))((jnp.array(1.0), jnp.array(1.0)))
  
imports: import warnings
  from typing import Union
  import equinox
  import jax
  import jax.numpy
  import jax.random
  import jax.tree_util
  import numpy
  import pytest
  from .helpers import tree_allclose
label_desc: Use image node_id 18 for calling a global function with example usage: test_filter_custom_vjp_defvjp() and returns: unknown,  unknown,  unknown, f,  None, unknown,  g2