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.

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)