public function send($method, $path = null, $data = [], array $options = []) {
		$defaults = ['return' => 'body'];
		$options += $defaults;
		$request = $this->_request($method, $path, $data, $options);
		$options += ['message' => $request];

		if (!$this->connection || !$this->connection->open($options)) {
			return;
		}
		$response = $this->connection->send($request, $options);
		$this->connection->close();

		if ($response->status['code'] == 401 && $auth = $response->digest()) {
			$request->auth = $auth;
			$this->connection->open(['message' => $request] + $options);
			$response = $this->connection->send($request, $options);
			$this->connection->close();
		}
		$this->last = (object) compact('request', 'response');

		$handlers = $this->_responseTypes;
		$handler = isset($handlers[$options['return']]) ? $handlers[$options['return']] : null;

		return $handler ? $handler($response) : $response;
	}