code: def _pre_parse_validation(email_header_fields):
      accepted_values = []
      for v in email_header_fields:
          if not _check_parenthesis(v):
              v = "('', '')"
          accepted_values.append(v)
  
      return accepted_values
  
imports: import os
  import re
  import time
  import datetime
  import urllib.parse
  from email._parseaddr import quote
  from email._parseaddr import AddressList
  from email._parseaddr import mktime_tz
  from email._parseaddr import parsedate, parsedate_tz, _parsedate_tz
label_desc: Use image node_id 8 for calling a global function with example usage: _pre_parse_validation(email_header_fields) and returns: accepted_values