code: def test_validate_minibatch_size_str(self):
      # Good descriptors.
      for s in [
          "32",
          "32,64",
          "1:32",
          "1:32,64",
          "64,1:32",
          "1:5,10:15",
          "128=64:128/256=32,64",
          "1=2/3=4",
          "1=1/2=2/3=3/4=4",
      ]:
          self.assertTrue(validate_minibatch_size_str(s), s)
      # Bad descriptors.
      for s in [
          None,
          42,
          (43,),
          "",
          "1:",
          ":2",
          "3,",
          ",4",
          "5:6,",
          ",7:8",
          "9=",
          "10=10/",
          "11=11/11",
          "12=1:2//13=1:3" "14=/15=15",
          "16/17=17",
          "/18=18",
          "/18",
          "//19",
          "/",
      ]:
          self.assertFalse(validate_minibatch_size_str(s), s)
  
imports: from __future__ import division
  import argparse
  import glob
  import logging
  import os
  import math
  import re
  import shutil
  import libs.common
  from libs.nnet3.train.dropout_schedule import *
  import unittest
label_desc: Use image node_id 3 for calling the SelfTest obj's underlying member method code with example usage: obj.test_validate_minibatch_size_str() without return types