  def testBoostedTreesSparseAggregateStatsSecurity(self):
    node_ids = []
    gradients = [[1.0]]
    hessians = [[100.0]]
    feature_indices = [[0, 0, 0]]
    feature_values = [0, 0, 0]
    feature_shape = [0, 0, 0]
    max_splits = 100
    num_buckets = 100
    with self.assertRaises((errors.InvalidArgumentError, ValueError)):
      gen_boosted_trees_ops.boosted_trees_sparse_aggregate_stats(
          node_ids=node_ids,
          gradients=gradients,
          hessians=hessians,
          feature_indices=feature_indices,
          feature_values=feature_values,
          feature_shape=feature_shape,
          max_splits=max_splits,
          num_buckets=num_buckets)
A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit.