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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 set_item(self, key, url):
 """ Store the url value under the unique key. :Args: - key[str]: The unique id to which the item (in this case, url) would be stored. - value[str]: The actual url value to be stored. """

        if self._db.search(self._urls.key == key):
            self._db.update({'url': url}, self._urls.key == key)
        else:
            self._db.insert({'key': key, 'url': url})