<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(self, id):
 """ Retrieve a particular document using it's unique identifier. Example usage: >> documentcloud.documents.get('71072-oir-final-report') """

        data = self.fetch('documents/%s.json' % id).get("document")
        data['_connection'] = self._connection
        return Document(data)