code: def valid_axes(self):
      return [None, (), 0, 1, 2, (0, 1), (0, 2), (1, 2), (0, 1, 2)]
  
imports: import nvidia.dali.fn
  from nvidia.dali.pipeline import Pipeline
  from nose.tools import nottest
  import numpy
  from test_utils import np_type_to_dali
  from nose_utils import assert_raises
label_desc: Use image node_id 2 for calling the Batch3D obj's underlying member method code with example usage: obj.valid_axes() and returns: list