def string_transformer(s: str) -> str:
	"""
	Given a string, return a new string that has
	transformed based on the input:
		1. Change case of every character, ie. lower
		case to upper case, upper case to lower case.
		2. Reverse the order of words from the input.

	Note: You will have to handle multiple spaces, and
	leading/trailing spaces.

	You may assume the input only contain English
	alphabet and spaces.
	:param s:
	:return:
	"""
	s_arr = s.split(' ')[::-1]

	for i, word in enumerate(s_arr):
		s_arr[i] = ''.join((char.upper() if char.islower() else char.lower()) for char in word)

	return ' '.join(s_arr)