code: def get_subword_prefix(self):
      if self.model_type in ["bart", "roberta"]:
          return "Ġ"
      if self.model_type in ["xlnet"]:
          return "▁"
      if self.model_type in ["bert"]:
          return "##"
  
imports: import numpy
  import string
  import nlpaug.util.selection.filtering
label_desc: Use image node_id 17 for calling the LanguageModels obj's underlying member method code with example usage: obj.get_subword_prefix() and returns: str, str, str