public function setEntityClass($className)
    {
        if (
            !class_exists($className) ||
            !is_subclass_of($className, EntityInterface::class)
        ) {
            throw new InvalidEntityClassException(
                "Class '{$className}' does not implements the " .
                "Slick\Orm\EntityInterface interface."
            );
        }
        
        $this->entityClass = $className;
        return $this;
    }