void IPortable.ReadPortable(IPortableReader reader)
 {
     _id = reader.ReadLong("id");
     _handle = reader.ReadPortable<Handle>("handle");
 }
 public bool Equals(Handle other)
 {
     return _handle == other._handle;
 }
 public Header(long id, Handle handle)
 {
     _id = id;
     _handle = handle;
 }