input: Write a function to take in two strings as input and return a list of all the words from both strings combined. The function should split each string into individual words and then concatenate the resulting lists.
  
  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", "Goodbye world") == ['Hello', 'world', 'Goodbye', 'world']
  assert string_to_list("", "No words here") == ['No', 'words', 'here']
  assert string_to_list("Just a single string", "") == ['Just', 'a', 'single', 'string']
  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