function test_printPong()
{
//Arrange
$test_PingPongGenerator = new PingPongGenerator();
$input = '15';
//Act
$result = $test_PingPongGenerator->makeNumberList($input);
//Assert
$this->assertEquals('1,2,PING,4,PONG,PING,7,8,PING,PONG,11,PING,13,14,PINGPONG', $result);
}
