code: def testGenerateShardedFilenames(self, spec, expected):
      names = io.generate_sharded_filenames(spec)
      self.assertEqual(names, expected)
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  from absl.testing import absltest
  from absl.testing import parameterized
  from third_party.nucleus.io import sharded_file_utils
  from third_party.nucleus.testing import test_utils
label_desc: Use image node_id 3 for calling the ShardsTest obj's underlying member method code with example usage: obj.testGenerateShardedFilenames(spec, expected) without return types