class_docstr: A custom subclass of 'logging.Logger' that keeps a set of messages to
  implement {debug,info,etc.}_once() methods.
class_docstr_tok: ["A","custom","subclass","of","'logging.Logger","'","that","keeps","a","set","of","messages","to","implement","{","debug",",","info",",","etc",".","}","_once","(",")","methods","."]
code: def warning_once(self, msg, *args, **kwargs):
      if msg not in self._seen_msgs:
          self.warning(msg, *args, **kwargs)
          self._seen_msgs.add(msg)
  
file_path: allennlp/allennlp/common/logging.py
imports: import logging
  from logging import Filter
  import os
  from os import PathLike
  from typing import Union
  import sys
label_desc: Use image node_id 4 for calling the AllenNlpLogger obj's underlying member method code with example usage: obj.warning_once(msg) without return types