code: def _check_for_dictionary_key(self, logical_id, dictionary, keys):
          
          for key in keys:
              if key not in dictionary:
                  raise InvalidResourceException(logical_id, 'Resource is missing the required [{}] '
                                                             'property.'.format(key))
docs: Checks a dictionary to make sure it has a specific key. If it does not, an
          InvalidResourceException is thrown.
  
          :param string logical_id: logical id of this resource
          :param dict dictionary: the dictionary to check
          :param list keys: list of keys that should exist in the dictionary