code: def test_verify_valid_vocab(vocab, expected_result):
      assert is_valid_vocab(vocab) == expected_result
  
file_path: sockeye/test/unit/test_vocab.py
imports: import pytest
  from unittest import mock
  from collections import Counter
  import sockeye.constants
  from sockeye.vocab import build_vocab, get_ordered_tokens_from_vocab, is_valid_vocab, _get_sorted_source_vocab_fnames, count_tokens
label_desc: Use image node_id 6 for calling a global function with example usage: test_verify_valid_vocab(vocab, expected_result) without return types