public function makeAbsolutePath($base)
	{
		if (is_string($base)) {
			$baseUrl = new Url($base);
		} else if ($base instanceof Url) {
			$baseUrl = $base;
		} else if ($newUrl instanceof Path) {
			$baseUrl = new Url();
			$baseUrl->path->set($newUrl);
		} else {
			throw new InvalidUrlException();
		}
		if ($baseUrl->isEmpty()) {
			throw new InvalidUrlException();
		}
		if (! $baseUrl->path->isAbsolute()) {
			throw new InvalidUrlException();
		}
		if ($this->isAbsolute()) {
			return $this;
		}
		if (! $this->path->isAbsolute()) {
			$relPath = Path::info($this->path->get());
			$baseDir = Path::info($baseUrl->path->get())->dir();
			$absPath = $relPath->abs($baseDir)->normalize();
			$this->path->set($absPath);
		}
		return $this;
	}