code: def test_multiple_nests(dev, input, num):
      def f(input, num):
          if num == -2:
              if num == -1:
                  if num == 0:
                      if num == 1:
                          if num == 2:
                              if num > 3:
                                  output = input - 100
                              else:
                                  output = input + 100
                          else:
                              output = input - 200
                      else:
                          output = input + 400
                  else:
                      output = input - 800
              else:
                  output = input + 1600
          else:
              output = input - 3200
          return output
  
      generic_execute(f, [input, num], [{"device": dev}, {}])
  
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 20 for calling a global function with example usage: test_multiple_nests(dev, input, num) and returns: output