问EF code-first是否需要导航属性来删除多对多关系？

EN

public class User() { 
   public int Id { get; set; }
   public string Name { get; set; }
   public List<Role> Roles { get; set; }
}

public class Role() { 
   public int Id { get; set; }
   public string Name { get; set; }
}

//... Mapping Config ...//
this.HasMany(x => x.Roles)
   .WithMany(/*can't be expressed without navigation property*/)
   .Map(m => {
      m.MapLeftKey("Users_Id");
      m.MapRightKey("Roles_Id");
      m.ToTable("UserRoleLinks");
   });

//... Deleting a Role that is in use ...//
using(var ctx = new MyDbContext()) {
    var role = ctx.Roles.Find(1);
    ctx.Roles.Remove(role);
    ctx.SaveChanges();
}