code: def testDropvar(self):
      def inner(x):
          return x * 2, x * 3
  
      def f(x):
          _, y = jit(inner)(x)
          return y * 4
  
      x_dense = jnp.arange(5)
      x_sparse = BCOO.fromdense(x_dense)
      self.assertArraysEqual(
          self.sparsify(f)(x_sparse).todense(), f(x_dense)
      )
  
imports: from functools import partial
  import math
  import operator
  from absl.testing import absltest
  from absl.testing import parameterized
  import numpy
  import jax
  from jax import config, jit, lax
  import jax.numpy
  import jax._src.test_util
  from jax.experimental.sparse import BCOO, BCSR, sparsify, todense, SparseTracer
  from jax.experimental.sparse.transform import arrays_to_spvalues, spvalues_to_arrays, sparsify_raw, SparsifyValue, SparsifyEnv
  from jax.experimental.sparse.util import CuSparseEfficiencyWarning
  from jax.experimental.sparse import test_util
label_desc: Use image node_id 6 for calling the SparsifyTest obj's underlying member method code with example usage: obj.testDropvar() and returns: unknown,  unknown, unknown