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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 delete_dbinstance(self, id, skip_final_snapshot=False, final_snapshot_id=''):
 """ Delete an existing DBInstance. :type id: str :param id: Unique identifier for the new instance. :type skip_final_snapshot: bool :param skip_final_snapshot: This parameter determines whether a final db snapshot is created before the instance is deleted. If True, no snapshot is created. If False, a snapshot is created before deleting the instance. :type final_snapshot_id: str :param final_snapshot_id: If a final snapshot is requested, this is the identifier used for that snapshot. :rtype: :class:`boto.rds.dbinstance.DBInstance` :return: The deleted db instance. """

        params = {'DBInstanceIdentifier' : id}
        if skip_final_snapshot:
            params['SkipFinalSnapshot'] = 'true'
        else:
            params['SkipFinalSnapshot'] = 'false'
            params['FinalDBSnapshotIdentifier'] = final_snapshot_id
        return self.get_object('DeleteDBInstance', params, DBInstance)