final class Test {
	private $value;

	private function __construct() {
	}

	/* This is singleton */
	public function getInstance() {
		static $instance;
		if(!$instance) {
			$instance = new Test();
		}
		return $instance;
	}

	public function get() {
		return $this->value;
	}

	public function set($value = 0) {
		$this->value = $value;
	}
}

final class Program {
	public function main() {
		$testA = Test::getInstance();
		$testA->set(5);
		$testB = Test::getInstance();
		var_dump($testB->get());
	}
} /* class */