@Override
    public void endDocument() throws SAXException {
        for (Map.Entry<String, Locator> entry : usemapLocationsByName.entrySet()) {
            if (!mapNames.contains(entry.getKey())) {
                err("The hash-name reference in attribute \u201Cusemap\u201D"
                    + " referred to \u201C"
                        + entry.getKey()
                        + "\u201D, but there is no \u201Cmap\u201D element"
                        + " with a \u201Cname\u201D attribute with that value.",
                        entry.getValue());
            }
        }
    }
@see org.xml.sax.helpers.XMLFilterImpl#endDocument()
src/nu/validator/checker/UsemapChecker.java