public class TagProgramMap : EntityTypeConfiguration<TagProgram> {
        public override void Map(EntityTypeBuilder<TagProgram> builder) {
            builder.HasKey(t => new { t.ProgramId, t.TagId });
            builder.HasOne(t => t.Tag).WithMany(t => t.TagPrograms).HasForeignKey(t => t.TagId)
                .OnDelete(DeleteBehavior.Restrict);
            builder.HasOne(t => t.Program).WithMany(t => t.TagPrograms).HasForeignKey(t => t.ProgramId)
                .OnDelete(DeleteBehavior.Restrict);
        }
    }