input: Write a python function to recognize a date (in DD/MM/YYYY format) in a string.
  assert recognize_date("Today's date is 12/09/2023.") == '12/09/2023'
  assert recognize_date("No date here!") == None
  assert recognize_date("Event will be held on 05/11/2022 at the venue.") == '05/11/2022'
  assert recognize_date("Incorrect formats like 2023/09/12 should not be recognized.") == None
output: def recognize_date(s: str) -> str:
      import re
      match = re.search(r'\b\d{2}/\d{2}/\d{4}\b', s)
      if match:
          return match.group(0)
      return None