code: def get_start_token(self):
      if self.model_type in ["bart", "roberta"]:
          return "<s>"
      if self.model_type in ["bert"]:
          return "[CLS]"
  
imports: import numpy
  import string
  import nlpaug.util.selection.filtering
label_desc: Use image node_id 12 for calling the LanguageModels obj's underlying member method code with example usage: obj.get_start_token() and returns: str, str