code: def test_zakharov(self):
      def zakharov_fn(x):
          ii = jnp.arange(1, len(x) + 1, step=1, dtype=x.dtype)
          answer = zakharovFromIndices(x=x, ii=ii)
          return answer
  
      x0 = jnp.array([600.0, 700.0, 200.0, 100.0, 90.0, 1e4])
      eval_func = jax.jit(zakharov_fn)
      jax_res = jax.scipy.optimize.minimize(
          fun=eval_func, x0=x0, method="BFGS"
      )
      self.assertLess(jax_res.fun, 1e-6)
  
imports: from absl.testing import absltest
  import numpy
  import scipy
  import scipy.optimize
  from jax import numpy
  from jax._src import test_util
  from jax import jit
  from jax import config
  import jax.scipy.optimize
label_desc: Use image node_id 3 for calling the TestBFGS obj's underlying member method code with example usage: obj.test_zakharov() and returns: answer