docs: @Override
      public V put(K key, V value)
      {
          BinarySet<Entry<K,V>> es = (BinarySet<Entry<K,V>>) entrySet;
          Entry<K,V> oldEntry = es.addEntry(entry(key, value));
          if (oldEntry != null)
          {
              return oldEntry.getValue();
          }
          return null;
      }