(PHP 5, PHP 7)
ReflectionClass::isSubclassOf — Checks if a subclass
public ReflectionClass::isSubclassOf ( mixed $class ) : bool
Checks if the class is a subclass of a specified class or implements a specified interface.
class
Either the name of the class as string or a ReflectionClass object of the class to check against.
 Returns true on success or false on failure. 
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    https://www.php.net/manual/en/reflectionclass.issubclassof.php