public void addTagLibraryResolver(PrefixTagLibraryResolver resolver) {
public void addTagLibraryResolver(TagLibraryResolver resolver) {
    public void addTagLibraryResolver(PrefixTagLibraryResolver resolver) {        String uriPrefix = resolver.uriPrefix();        if (uriPrefix.length() == 0)            throw new IllegalArgumentException("resolver prefix is empty");        prefixResolvers.put(uriPrefix, resolver);    }