<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def get_multi_word_keywords(features):
 """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 """

        keys = {
            'is not': Token(TokenTypes.NOT_EQUAL, 'is not'),
        }
        return OrderedDict(sorted(list(keys.items()), key=lambda t: len(t[0]), reverse=True))