public static async Task <ContentManageResult> AddDeflistAsync(NiconicoContext context, NiconicoItemType item_type, string item_id, string description)
{
var dict = new Dictionary <string, string>();
var group_id = "default";
var mylistToken = await context.GetMylistToken(group_id, item_id);
dict.Add(nameof(group_id), group_id);
dict.Add(nameof(item_type), ((uint)item_type).ToString());
dict.Add(nameof(item_id), mylistToken.ItemId);
dict.Add(nameof(description), description);
dict.Add("token", mylistToken.Token);
var json = await context.PostAsync(NiconicoUrls.MylistDeflistAddUrl, dict, withToken : false);
return(ContentManagerResultHelper.ParseJsonResult(json));
}