code: public synchronized TreeEntry<K, V> pollLastEntry() {
  		final TreeEntry<K, V> entry = lastEntry();
  		if (entry != null) {
  			remove(entry.getKey());
  		}
  		return entry;
  	}
docs: Removes and returns a key-value mapping associated with the greatest key in this map, or null if the
  map is empty.
  
  @return entry