contain object type element contain item uid extract item uid exist assign object param content except sax except got element content sax except contain pgml handler object pgml stack parser diagram item uid item uid uid item uid content uid item uid set item uid uid us pgml handler contain fig group handler object fig group handler contain fig group item uid item uid uid item uid content uid item uid set item uid uid contain fig edg handler object fig edg handler contain fig edg item uid item uid uid item uid content uid item uid set item uid uid handl us content got element content 