protected function &getSource($src)
	{
		if (!isset($this->sources[$src]))
		{
			if (is_readable($src))
			{
				$this->sources[$src] = self::splitLines(file_get_contents($src));
			}
			else
			{
				$this->sources[$src] = null;
			}
		}

		return $this->sources[$src];
	}