question: TagStack ( TagElement tag , TagStack next ) { this . tag = tag ; this . elem = tag . getElement ( ) ; this . next = next ; Element elem = tag . getElement ( ) ; if ( elem . getContent ( ) != null ) { this . state = new ContentModelState ( elem . getContent ( ) ) ; } if ( next != null ) { inclusions = next . inclusions ; exclusions = next . exclusions ; pre = next . pre ; } if ( tag . isPreformatted ( ) ) { pre = true ; } if ( elem . inclusions != null ) { if ( inclusions != null ) { inclusions = ( BitSet ) inclusions . clone ( ) ; inclusions . or ( elem . inclusions ) ; } else { inclusions = elem . inclusions ; } } if ( elem . exclusions != null ) { if ( exclusions != null ) { exclusions = ( BitSet ) exclusions . clone ( ) ; exclusions . or ( elem . exclusions ) ; } else { exclusions = elem . exclusions ; } } }
target:  Construct a stack element.