src/Viserio/Component/StaticalProxy/StaticalProxy.php
protected static function isMock(): bool
    {
        $name = static::getInstanceIdentifier();

        return isset(static::$resolvedInstance[$name]) &&
                static::$resolvedInstance[$name] instanceof MockInterface;
    }
protected static function isMock(): bool
    {
        $name = static::getInstanceIdentifier();

        return isset(static::$resolvedInstance[$name]) &&
                static::$resolvedInstance[$name] instanceof MockInterface;
    }
Determines whether a mock is set as the instance of the static proxy.

@return bool