Value cannot be added to the property bag because it is not Cloneable and serializable .
值不能添加到属性包，因为它无法克隆，也无法序列化。
Collection classes are wrapped in appropriate wrappers , and arrays ( and other cloneable objects ) are cloned .
集合类被封装在适当的包装器中，数组（及其他可克隆的对象）被克隆。
cloneable