public string HTMLGetRankedConcepts(string html, string url, AlchemyAPI_ConceptParams parameters)
        {
            CheckHTML(html, url);
            parameters.setHtml(html);
            parameters.setUrl(url);

            return POST("HTMLGetRankedConcepts", "html", parameters);
        }
        public string TextGetRankedConcepts(string text, AlchemyAPI_ConceptParams parameters)
        {
            CheckText(text);
            parameters.setText(text);

            return POST("TextGetRankedConcepts", "text", parameters);
        }
        public string URLGetRankedConcepts(string url, AlchemyAPI_ConceptParams parameters)
        {
            CheckURL(url);
            parameters.setUrl(url);

            return GET("URLGetRankedConcepts", "url", parameters);
        }