code: public synchronized TreeEntry<K, V> lowerEntry(final K key) {
  		// Retorna la clave mas cercana menor a la clave indicada
  		return getRoundEntry(key, false, false);
  	}
docs: Returns the greatest key strictly less than the given key, or null if there is no such key.
  
  @param key the key
  @return the Entry with greatest key strictly less than the given key, or null if there is no such key.