protected function buildPaths ()
		{
			$titles = [];
			$guids = [];

			$n = count($this->_data);
			for ($i = 0; $i < $n; $i++)
			{
				$parent = $this->_data[ $i ];
				for ($j = $i + 1; $j < $n; $j++)
				{
					$child = $this->_data[ $j ];
					if ($child->lft > $parent->lft and $child->rgt < $parent->rgt)
					{
						$titles[ $child->id ][] = $parent->title;
						$guids[ $child->id ][] = $parent->guid;
					}
				}
				$titles[ $parent->id ][] = $parent->title;
				$guids[ $parent->id ][] = $parent->guid;

				$parent->titlePath = implode($this->_titlePathDelimiter, $titles[ $parent->id ]);
				$parent->guidPath = implode($this->_guidPathDelimiter, $guids[ $parent->id ]);
			}
		}