public string GetAll(string username, VimeoChannelsSort sort, int page, int perPage)
        {
            // Initialize the query string
            NameValueCollection query = new NameValueCollection {
                { "format", "json" },
                { "method", "vimeo.channels.getAll" }
            };

            // Add optional parameters
            if (!String.IsNullOrEmpty(username))
            {
                query.Add("user_id", username);
            }
            if (sort != VimeoChannelsSort.Default)
            {
                query.Add("sort", SocialUtils.CamelCaseToUnderscore(sort));
            }
            if (page > 0)
            {
                query.Add("page", page + "");
            }
            if (perPage > 0)
            {
                query.Add("per_page", perPage + "");
            }

            // Call the Vimeo API
            return(Client.DoHttpRequestAsString("GET", "http://vimeo.com/api/rest/v2", query, null));
        }