public function add($owner, $repo, $number, array $labels)
	{
		// Build the request path.
		$path = '/repos/' . $owner . '/' . $repo . '/issues/' . $number . '/labels';

		// Send the request.
		return $this->processResponse(
			$this->client->post($this->fetchUrl($path), json_encode($labels))
		);
	}