code: def check(text):
      
      err = "security.credit_card"
      msg = u"Don't put credit card numbers in plain text."
  
      credit_card_numbers = [
          "4\d{15}",
          "5[1-5]\d{14}",
          "3[4,7]\d{13}",
          "3[0,6,8]\d{12}",
          "6011\d{12}",
      ]
  
      return existence_check(text, credit_card_numbers, err, msg)
docs: Check the text.