input: Write a function to take in two strings as input, and output a list of all the words in both strings.
  
  def string_to_list(s1, s2):
      s1_list = s1.split()
      s2_list = s2.split()
      output_list = s1_list + s2_list
      return output_list
  
  assert string_to_list("I want to make a difference", "The journey to success is long") == ["I", "want", "to", "make", "a", "difference", "The", "journey", "to", "success", "is", "long"]
  assert string_to_list("Hello world", "Python is fun") == ["Hello", "world", "Python", "is", "fun"]
  assert string_to_list("", "Empty string test") == ["Empty", "string", "test"]
  assert string_to_list("Single", "") == ["Single"]
  assert string_to_list("", "") == []
output: def string_to_list(s1, s2):
      s1_list = s1.split()
      s2_list = s2.split()
      output_list = s1_list + s2_list
      return output_list