code: def testPytreeInput(self):
      f = self.sparsify(lambda x: x)
      args = (jnp.arange(4), BCOO.fromdense(jnp.arange(4)))
      out = f(args)
      self.assertLen(out, 2)
      self.assertArraysEqual(args[0], out[0])
      self.assertBcooIdentical(args[1], out[1])
  
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 7 for calling the SparsifyTest obj's underlying member method code with example usage: obj.testPytreeInput() without return types