public Book(BookViewModel bvm)
        {
            // TODO: Complete member initialization
            this.bvm_ = bvm;

            this.log_ = new ErrLog();

        }
        //private DateTime referenceDate_;

        public Instrument_hifive()
        {
            this.InstVM_ = new Excel_instrument_hifiveViewModel(true);
            this.ErrLog_ = new ErrLog();
        }