appli list valu pair properti model element treat tag tag valu unless properti special string action properti special invok param elem model element appli properti param prop list valu pair properti param spec arrai properti special string us set properti object elem list prop properti special spec valu prop prop size prop valu prop trim valu valu valu trim current properti occur second time given list properti skip prop size prop equal ignor trim prop spec spec length spec invok elem valu prop model core helper set tag valu elem valu 