question: protected final void checkNamespaceWF ( String qname , int colon1 , int colon2 ) { if ( ! errorChecking ) { return ; } if ( colon1 == 0 || colon1 == qname . length ( ) - 1 || colon2 != colon1 ) { String msg = DOMMessageFormatter . formatMessage ( DOMMessageFormatter . DOM_DOMAIN , "NAMESPACE_ERR" , null ) ; throw new DOMException ( DOMException . NAMESPACE_ERR , msg ) ; } }
target:  Call user data handlers to let them know the nodes they are related to are being deleted. The alternative would be to do that on Node but because the nodes are used as the keys we have a reference to them that prevents them from being gc'ed until the document is. At the same time, doing it here has the advantage of avoiding a finalize() method on Node, which would affect all nodes and not just the ones that have a user data.