public static bool TryGetGraphdat(out IGraphdat graphdat)
{
graphdat = null;
var httpContext = HttpContext.Current;
if (httpContext == null) return false;
if (!httpContext.Items.Contains(ContextItemKey)) return false;
var api = httpContext.Items[ContextItemKey] as API;
if (api == null) return false;
graphdat = api;
return true;
}