EF 6：两个相同类型的集合

Question

假设我有以下类

public class Activity
{
    [Key]
    public int ActivityId { get; set;} 

    public virtual ICollection<ActivityConstraint> CreationConstraints { get; set; }

    public virtual ICollection<ActivityConstraint> ExecutionConstraints { get; set; }
}

public class ActivityConstraint
{
    [Key]
    public int ActivityConstraintId { get; set;} 

    [ForeignKey("Activity")]
    public virtual Activity Activity { get; set; }
}

我如何在EF 6中模拟这些实体？