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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 create(cls, record, bucket):
 """Create a new RecordsBuckets and adds it to the session. :param record: Record used to relate with the ``Bucket``. :param bucket: Bucket used to relate with the ``Record``. :returns: The :class:`~invenio_records_files.models.RecordsBuckets` object created. """

        rb = cls(record=record, bucket=bucket)
        db.session.add(rb)
        return rb