struct _zend_class_entry {
    ...
    //构造方法 __construct
    union _zend_function *constructor;
    //析构方法 __destruct
    union _zend_function *destructor;
    //克隆方法 __clone
    union _zend_function *clone;
    union _zend_function *__get;
    union _zend_function *__set;
    union _zend_function *__unset;
    union _zend_function *__isset;
    union _zend_function *__call;
    union _zend_function *__callstatic;
    union _zend_function *__tostring;
    //序列化
    union _zend_function *serialize_func;
    //反序列化
    union _zend_function *unserialize_func;
    ...
}