function test_pingPong_count()
{
//Arrange
$test_PingPong = new PingPongGenerator();
$input = 18;
//Act
$result = $test_PingPong->pingPong($input);
//Assert
$this->assertEquals([1, 2, "ping", 4, "pong", "ping", 7, 8, "ping", "pong", 11, "ping", 13, 14, "ping-pong", 16, 17, "ping"], $result);
}
