code: Node<K, V> findByEntry(Entry<?, ?> entry) {
      Node<K, V> mine = findByObject(entry.getKey());
      boolean valuesEqual = mine != null && equal(mine.value, entry.getValue());
      return valuesEqual ? mine : null;
    }
docs: Returns this map's entry that has the same key and value as {@code
  entry}, or null if this map has no such entry.
  
  <p>This method uses the comparator for key equality rather than {@code
  equals}. If this map's comparator isn't consistent with equals (such as
  {@code String.CASE_INSENSITIVE_ORDER}), then {@code remove()} and {@code
  contains()} will violate the collections API.