public function issues($owner, $repo, $state, $keyword)
	{
		if (\in_array($state, array('open', 'close')) == false)
		{
			throw new \UnexpectedValueException('State must be either "open" or "closed"');
		}

		// Build the request path.
		$path = '/legacy/issues/search/' . $owner . '/' . $repo . '/' . $state . '/' . $keyword;

		// Send the request.
		return $this->processResponse(
			$this->client->get($this->fetchUrl($path))
		);
	}