/// <summary>
 /// 初始化一个<see cref="ValueObjectSample"/>类型的实例
 /// </summary>
 public ValueObjectSample(string city, string street, AggregateRootSample sample, ValueObjectSample child)
 {
     City          = city;
     Street        = street;
     AggregateRoot = sample;
     Child         = child;
 }
 /// <summary>
 /// 初始化一个<see cref="ValueObjectSample"/>类型的实例
 /// </summary>
 public ValueObjectSample(string city, string street, AggregateRootSample sample) : this(city, street, sample, null)
 {
 }