code: def test_is_pipeline_def():
      @pipeline_def
      def pipe():
          return 42
  
      @pipeline_def()
      def pipe_unconf():
          return 42
  
      @pipeline_def(max_batch_size=1, num_threads=1, device_id=0)
      def pipe_conf():
          return 42
  
      assert getattr(pipe, "_is_pipeline_def", False)
      assert getattr(pipe_unconf, "_is_pipeline_def", False)
      assert getattr(pipe_conf, "_is_pipeline_def", False)
  
file_path: DALI/dali/test/python/test_pipeline_decorator.py
imports: from nvidia.dali import Pipeline, pipeline_def
  from nose.tools import nottest
  from nose_utils import raises
  import nvidia.dali.fn
  from test_utils import get_dali_extra_path, compare_pipelines
  import os
label_desc: Use image node_id 11 for calling a global function with example usage: test_is_pipeline_def() and returns: int, int, int