question: @ SuppressWarnings ( "unchecked" ) public < T extends PO > T first ( ) throws DBException { T po = null ; String sql = buildSQL ( null , true ) ; PreparedStatement pstmt = null ; ResultSet rs = null ; try { pstmt = DB . prepareStatement ( sql , trxName ) ; rs = createResultSet ( pstmt ) ; if ( rs . next ( ) ) { po = ( T ) table . getPO ( rs , trxName ) ; } } catch ( SQLException e ) { log . log ( Level . SEVERE , sql , e ) ; throw new DBException ( e , sql ) ; } finally { DB . close ( rs , pstmt ) ; rs = null ; pstmt = null ; } return po ; }
target:  Return first PO that match query criteria