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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 load(cls, database, doc_id):
 """Load a specific document from the given database. :param database: the `Database` object to retrieve the document from :param doc_id: the document ID :return: the `Document` instance, or `None` if no document with the given ID was found """

        doc = database.get(doc_id)
        if doc is None:
            return None
        return cls.wrap(doc)