code: def main():
      exit_code = 0
  
      with open(LEGAL_HEADER_FILE) as header_f:
          header = header_f.read()
  
      # find all .py files recursively
      files = [
          new_file
          for path in PATHS_REQUIRING_HEADER
          for new_file in files_at_path(path)
      ]
  
      # find all files which do not contain the header and are non-empty
      files_with_missing_header = list(
          files_missing_substring(files, header)
      )
  
      # exit with an error and print all files without header in read, if any
      if files_with_missing_header:
          print(
              RED_COLOR
              + "The legal header is missing from the following files:\n- "
              + "\n- ".join(files_with_missing_header)
              + NO_COLOR
              + "\nPlease add it by copy-pasting the below:\n\n"
              + header
              + "\n"
          )
          exit_code = 1
  
      # check the LICENSE.md exists and has the right contents
      try:
          files = list(files_missing_substring([LICENSE_MD], LICENSE))
          if files:
              print(
                  RED_COLOR
                  + "Please make sure the LICENSE.md file "
                  + "at the root of the project "
                  + "has the right contents."
                  + NO_COLOR
              )
              exit(1)
      except IOError:
          print(
              RED_COLOR
              + "Please add the LICENSE.md file at the root of the project "
              "with the appropriate contents." + NO_COLOR
          )
          exit(1)
  
      # if it doesn't exist, send a notice
      exit(exit_code)
  
label_desc: Use image node_id 3 for calling a global function with example usage: main() without return types