@Override public void set(Boolean newValue) { Boolean oldValue = get(); if (equals(oldValue, newValue)) { return; } if (newValue != null) { // Add an element to reflect new value. getDocument().createChildElement(container, tag, new AttributesImpl(valueAttr, Serializer.BOOLEAN.toString(newValue))); cleanup(); } else { // Erase all elements. Cleanup first, so that removal of real element // does not promote a redundant element temporarily. cleanup(); getDocument().deleteNode(valueElement); } assert equals(newValue, get()); }