code: def is_disjoint(set1, set2, warn):
      
      for elem in set2:
          if elem in set1:
              raise ValueError(warn)
      return True
docs: Checks if elements of set2 are in set1.
  
      :param set1: a set of values
      :param set2: a set of values
      :param warn: the error message that should be thrown
       when the sets are NOT disjoint
      :return: returns true no elements of set2 are in set1