class_docstr: Abstract class for tokenizer.
code: def vocab_size(self):
      pass
  
imports: from abc import ABC, abstractmethod
  from colossalai.legacy.context import ParallelMode
  from colossalai.legacy.core import global_context
  from .bert_tokenization import FullTokenizer
label_desc: Use image node_id 2 for calling the AbstractTokenizer obj's underlying member method code with example usage: obj.vocab_size() without return types