/src/main/java/org/htmlunit/html/HtmlElement.java
if ( notifyMutationObservers) {
if ( mappedElement ) {
public Attr setAttributeNode(final Attr attribute) { final String qualifiedName = attribute.getName(); final String oldAttributeValue = getAttribute(qualifiedName); final HtmlPage htmlPage = (HtmlPage) getPage(); final boolean mappedElement = isAttachedToPage() && HtmlPage.isMappedElement(htmlPage, qualifiedName); <extra_id_0> htmlPage.removeMappedElement(this); } final HtmlAttributeChangeEvent event; if (ATTRIBUTE_NOT_DEFINED == oldAttributeValue) { event = new HtmlAttributeChangeEvent(this, qualifiedName, attribute.getValue()); }