+/**
+ * Common marker interface for nodes which act as an immutable {@link Entry}.
+ *
+ * @author Robert Varga
+ *
+ * @param <K> the type of key
+ * @param <V> the type of value
+ */
+interface EntryNode<K, V> extends Entry<K, V> {
+ @Override
+ default public V setValue(final V value) {
+ throw new UnsupportedOperationException();
+ }