input: Write a python function to toggle the case of characters in a string based on a given list of characters.
  assert toggle_case("hello world", "aeiou") == "hEllO wOrld"
  assert toggle_case("HELLO WORLD", "aeiou") == "HELLO WORLD"
  assert toggle_case("Python Programming", "prgmn") == "pYTHON pRoGRaMMING"
output: def toggle_case(s, chars):
      chars_set = set(chars)
      result = []
      for c in s:
          if c.lower() in chars_set or c.upper() in chars_set:
              if c.islower():
                  result.append(c.upper())
              else:
                  result.append(c.lower())
          else:
              result.append(c)
      return ''.join(result)