public void playerHitCheck()
{
Rulebook rulebook = new Rulebook();
Rulebook rb = rulebook;
rb.playerHitTimer = 16.0f;
rb.enemyHitPlayer = 5;
rb.enemyDamageHits = 5;
Assert.Throws <NullReferenceException>(() => rb.PlayerHitCheck());
Assert.That(rb.playerHitTimer, Is.EqualTo(0.0f));
}