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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:

def limit(self, keys):
        ''' Remove all keys other than the keys specified.
        '''
        if not isinstance(keys, list) and not isinstance(keys, tuple):
            keys = [keys]
        remove_keys = [k for k in self.keys() if k not in keys]
        for k in remove_keys:
            self.pop(k)