code: def test_very_roughly_three_channels(self):
      self._test_very_roughly(3)
  
imports: from __future__ import print_function, division, absolute_import
  import sys
  import numpy
  import cv2
  import imgaug
  from imgaug import augmenters
  from imgaug import parameters
  from imgaug.testutils import reseed, runtest_pickleable_uint8_img, is_parameter_instance
label_desc: Use image node_id 3 for calling the TestSnowflakes obj's underlying member method code with example usage: obj.test_very_roughly_three_channels() without return types