code: def read_file(self, fn):
      try:
          with open(fn, "r", encoding="utf-8") as f:
              self.text = f.read()
          yield self.text
          self.text = None
      except UnicodeDecodeError:
          print("{} is invalid text file, skipped!".format(fn))
          yield None
  
imports: import argparse
  import os
  import pathlib
  import re
  import subprocess
  from tqdm import tqdm
  from contextlib import contextmanager
label_desc: Use image node_id 5 for calling the Checker obj's underlying member method code with example usage: obj.read_file(fn) without return types