input: def get_word_lists(strings: List[str]) -> List[List[str]]:
      """ Generate a list of lists of words from the given list of strings. 
      The returned list should have the first word for each string followed by 
      following words for each string.
      >>> get_word_lists(["Hello world", "This is a test"])
      [['Hello', ['Hello', 'world']], ['This', ['This', 'is'], ['This', 'is', 'a'], ['This', 'is', 'a', 'test']]]
      """
output:     result = []
      for string in strings:
          words = string.split()
          first_word = words[0]
          word_lists = [[first_word]]
          for i in range(1, len(words)):
              word_lists.append(words[:i+1])
          result.append([first_word, word_lists])
      return result