 parks[0].AddAmenity(tennis); parks[0].AddAmenity(restrooms); ParksRepos.SavePark(parks[0]);  parks[0].AddAmenity(tennis); parks[0].AddAmenity(restrooms); ParksRepos.SavePark(parks[0]);  parks[0].AddAmenity(restrooms); ParksRepos.SavePark(parks[0]);  