input: def sort_strings_by_length(strings: List[str]) -> List[str]:
      """ Sort a list of strings based on their length.
      >>> sort_strings_by_length(["Hello", "World!", "Good", "Morning"])
      ["Good", "Hello", "World!", "Morning"]
      >>> sort_strings_by_length(["a", "bb", "ccc", "dddd"])
      ["a", "bb", "ccc", "dddd"]
      """
output:     return sorted(strings, key=len)