If the visibility of a property has changed between serialization and
unserialization, or if a private or protected property needs to be
restored, but the serialized data was generated by a __serialize method
while no __unserialize method exists in the class, the property value
cannot be found during hydration in the object's hash table. The reason
for this is that in these cases the property name in the serialized
representation does not match the prefixed/mangled property name of the
current class definition. To resolve this, an attempt is made to
determine the correctly prefixed property name by performing a lookup
with the unprefixed property name in the properties_info hash table
of the class. The implementation is borrowed from the current version of
php-src/ext/standard/var_unserializer.re to align the behavior to the
serializer of PHP >= 7.2. See 7cb5bdf64a95bd70623d33d6ea122c13b01113bd /
php/php-src#2494 for the initial implementation in PHP 7.2.