input: Write a function to check if a given string contains all the words in a list. If all words are found in the string, return True; otherwise, return False.
  def contains_words(input_string, words):
   for word in words:
   if word not in input_string:
   return False
   return True
  
  assert contains_words('This is a test', ['test', 'this', 'is'])==True
  assert contains_words('This is a test', ['test', 'this', 'not'])==False
  assert contains_words('This is a test', ['this', 'is', 'a'])==True
  assert contains_words('This is a test', ['test', 'a', 'this'])==True
  assert contains_words('This is a test', ['test', 'none', 'words'])==False
output: def contains_words(input_string, words):
   for word in words:
   if word.lower() not in input_string.lower():
   return False
   return True