code: def test_basic(num_gen):
      def f(n):
          a = np.int32(0)
          b = np.int32(0)
          if n > 0:
              a = -n
          else:
              b = 2 * n
          return a, b
  
      generic_execute(f, [num_gen])
  
imports: from nvidia.dali.pipeline import pipeline_def, experimental
  import nvidia.dali.fn
  import nvidia.dali.types
  from nvidia.dali.types import SampleInfo
  from nvidia.dali import _conditionals
  from nvidia.dali.data_node import DataNode
  import numpy
  import os
  from test_utils import check_batch, compare_pipelines
  from nose_utils import assert_raises
  from test_utils import get_dali_extra_path
  from nose2.tools import params
  import itertools
label_desc: Use image node_id 3 for calling a global function with example usage: test_basic(num_gen) and returns: a,  b