public void Add_Instrument_Test()
{
Instrument toeTeVoegenInstrument = new Instrument(new InstrumentStruct("Fluit", 1));
studioInstrument.AddInstrument(toeTeVoegenInstrument);
List <IInstrument> instrumentList = studioInstrument.GetAllInstrumenten();
Assert.AreEqual(1, instrumentList.Count);
Assert.AreEqual(instrumentList[0].Naam, toeTeVoegenInstrument.Naam);
studioInstrument.RemoveInstrument(instrumentList[0].Id);
}