private static String getCause(int statusCode) {
		String cause = null;
		switch (statusCode) {
		case NOT_MODIFIED:
			break;
		case BAD_REQUEST:
			cause = "The request was invalid.  An accompanying error message will explain why. This is the status code will be returned during rate limiting.";
			break;
		case NOT_AUTHORIZED:
			cause = "Authentication credentials were missing or incorrect.";
			break;
		case FORBIDDEN:
			cause = "The request is understood, but it has been refused.  An accompanying error message will explain why.";
			break;
		case NOT_FOUND:
			cause = "The URI requested is invalid or the resource requested, such as a user, does not exists.";
			break;
		case NOT_ACCEPTABLE:
			cause = "Returned by the Search API when an invalid format is specified in the request.";
			break;
		case INTERNAL_SERVER_ERROR:
			cause = "Something is broken.  Please post to the group so the Weibo team can investigate.";
			break;
		case BAD_GATEWAY:
			cause = "Weibo is down or being upgraded.";
			break;
		case SERVICE_UNAVAILABLE:
			cause = "Service Unavailable: The Weibo servers are up, but overloaded with requests. Try again later. The search and trend methods use this to indicate when you are being rate limited.";
			break;
		default:
			cause = "";
		}
		return statusCode + ":" + cause;
	}