input: Write a function to generate a list of lists of words from a given list of strings. Each inner list should contain the first word of the string followed by the subsequent words in the string. If the list of strings is empty, return an empty list.
  assert get_word_lists(["Hello world", "This is a test"])==[["Hello", "world"], ["This", "is", "a", "test"]]
  assert get_word_lists(["One two", "Three four five"])==[["One", "two"], ["Three", "four", "five"]]
  assert get_word_lists(["Single"])==[["Single"]]
  assert get_word_lists([])==[]
output: def get_word_lists(strings):
      if not strings:
          return []
      result = []
      for s in strings:
          words = s.split()
          result.append(words)
      return result