code: def extract_file_header(self):
      extract_texts = self.header_extract_rule.findall(self.text)
      if len(extract_texts) == 0:
          return None
      return extract_texts[0]
  
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 7 for calling the Checker obj's underlying member method code with example usage: obj.extract_file_header() and returns: extract_texts, None