dom3 aselementdeclaration asobject empty_contenttype any_contenttype mixed_contenttype elements_contenttype getstrictmixedcontent setstrictmixedcontent strictmixedcontent asdatatype getelementtype setelementtype asdatatype elementtype getispcdataonly setispcdataonly ispcdataonly getcontenttype setcontenttype contenttype getsystemid setsystemid systemid ascontentmodel getascm setascm ascontentmodel ascm asnamedobjectmap getasattributedecls setasattributedecls asnamedobjectmap asattributedecls addasattributedecl asattributedeclaration attributedecl asattributedeclaration removeasattributedecl asattributedeclaration attributedecl