'Create a new DB snapshot.
:type snapshot_id: string
:param snapshot_id: The identifier for the DBSnapshot
:type dbinstance_id: string
:param dbinstance_id: The source identifier for the RDS instance from
which the snapshot is created.
:rtype: :class:`boto.rds.dbsnapshot.DBSnapshot`
:return: The newly created DBSnapshot'

def create_dbsnapshot(self, snapshot_id, dbinstance_id):

    params = {'DBSnapshotIdentifier': snapshot_id, 'DBInstanceIdentifier': dbinstance_id}
    return self.get_object('CreateDBSnapshot', params, DBSnapshot)
