public SpellResult CheckText(string text, Lang[] lang = null, SpellerOptions? options = null, OutputFormat? format = null)
		{
			RestRequest request = new RestRequest("checkText");
			request.AddParameter("text", text);
			if (lang != null && lang.Length != 0)
				request.AddParameter("lang", string.Join(",", lang.Select(l => l.ToString().ToLowerInvariant())));
			if (options.HasValue)
				request.AddParameter("options", (int)options.Value);
			if (format.HasValue)
				request.AddParameter("format", format.Value.ToString().ToLowerInvariant());

			return SendRequest<SpellResult>(request);
		}