protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
 {
     // Visual Studio 2015 | Use the LocalDb 12 instance created by Visual Studio
     optionsBuilder.UseSqlServerWithMaterialization(@"Server=(localdb)\mssqllocaldb;Database=Ef7Tests;Trusted_Connection=True;");
     // Visual Studio 2013 | Use the LocalDb 11 instance created by Visual Studio
     //optionsBuilder.UseSqlServer(@"Server=(localdb)\mssqllocaldb;Database=Ef7Tests;Trusted_Connection=True;");
 }