code: def get_multi_word_keywords(features):
          
          keys = {
              'is not': Token(TokenTypes.NOT_EQUAL, 'is not'),
          }
          return OrderedDict(sorted(list(keys.items()), key=lambda t: len(t[0]), reverse=True))
docs: This returns an OrderedDict containing the multi word keywords in order of length.
          This is so the tokenizer will match the longer matches before the shorter matches