对于多对多关系，如何直接填写EF Core生成的join表？

public class Student
{
    public int StudentId { get; set; }
    public string Name { get; set; }
    public ICollection<StudentCourse> StudentCourses { get; set; }
}

public class Course
{
    public int CourseId { get; set; }
    public string Title { get; set; }
    public ICollection<StudentCourse> StudentCourses { get; set; }
}

public class StudentCourse
{
    public int StudentId { get; set; }
    public Student Student { get; set; }

    public int CourseId { get; set; }
    public Course Course { get; set; }
}

public class SchoolContext : DbContext
{
    public DbSet<Student> Students { get; set; }
    public DbSet<Course> Courses { get; set; }
    public DbSet<StudentCourse> StudentCourses { get; set; }

    protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
        modelBuilder.Entity<StudentCourse>()
            .HasKey(sc => new { sc.StudentId, sc.CourseId });

        modelBuilder.Entity<StudentCourse>()
            .HasOne(sc => sc.Student)
            .WithMany(s => s.StudentCourses)
            .HasForeignKey(sc => sc.StudentId);

        modelBuilder.Entity<StudentCourse>()
            .HasOne(sc => sc.Course)
            .WithMany(c => c.StudentCourses)
            .HasForeignKey(sc => sc.CourseId);
    }
}

using (var context = new SchoolContext())
{
    var student = new Student { Name = "John" };
    var course = new Course { Title = "Math" };

    context.StudentCourses.Add(new StudentCourse { Student = student, Course = course });

    context.SaveChanges();
}