src/Reflection/ReflectionClass.php
public function isCloneable() : bool
    {
        if (! $this->isInstantiable()) {
            return false;
        }

        if (! $this->hasMethod('__clone')) {
            return true;
        }

        return $this->getMethod('__clone')->isPublic();
    }
public function isCloneable() : bool
    {
        if (! $this->isInstantiable()) {
            return false;
        }

        if (! $this->hasMethod('__clone')) {
            return true;
        }

        return $this->getMethod('__clone')->isPublic();
    }
Checks whether this is a reflection of a class that supports the clone operator

@link https://php.net/manual/en/reflectionclass.iscloneable.php