input: from typing import List
  
  
  def contain_common_words(str1: str, str2: str) -> List[str]:
      """ Take in two strings as input, and output a list of all the words present in either of the strings.
      >>> contain_common_words("I want to make a difference", "The journey to success is long")
      ['I', 'want', 'to', 'make', 'a', 'difference', 'The', 'journey', 'to', 'success', 'is', 'long']
      """
output:     words1 = set(str1.split())
      words2 = set(str2.split())
      return list(words1.union(words2))