public CollectionModel GetOpenedMeetings([FromUri] string keywords = "")
        {
            try {
                FixedList <Meeting> meetingList = Meeting.GetOpened(keywords);

                return(new CollectionModel(this.Request, meetingList.ToResponse(),
                                           typeof(Meeting).FullName));
            } catch (Exception e) {
                throw base.CreateHttpException(e);
            }
        }