public IEnumerator ActivateWithoutParametersTest()
        {
            // Given a valid confetti machine,
            GameObject      machineObject   = Object.Instantiate(Resources.Load <GameObject>(pathToDefaultPrefab));
            ConfettiMachine confettiMachine = machineObject.GetComponent <ConfettiMachine>();

            // When I call Activate without parameters on it,
            confettiMachine.Activate();

            // Then the confetti machine is active and all of its particle systems are active and playing.
            Assert.IsTrue(confettiMachine.IsActive);

            ParticleSystem[] particleSystems = machineObject.GetComponentsInChildren <ParticleSystem>();
            Assert.IsTrue(particleSystems.Length > 0);

            foreach (ParticleSystem particleSystem in particleSystems)
            {
                Assert.IsTrue(particleSystem.isPlaying);
            }

            yield break;
        }
        public IEnumerator ChangeToZeroAreaRadiusTest()
        {
            // Given a valid confetti machine with particle systems and a area radius equals zero,
            GameObject      machineObject   = Object.Instantiate(Resources.Load <GameObject>(pathToDefaultPrefab));
            ConfettiMachine confettiMachine = machineObject.GetComponent <ConfettiMachine>();

            ParticleSystem[] particleSystems = machineObject.GetComponentsInChildren <ParticleSystem>(true);
            Assert.IsTrue(particleSystems.Length > 0);

            float newRadius = 0f;

            // When I change the area radius,
            confettiMachine.ChangeAreaRadius(newRadius);

            // Then the radius is changed to 0.01f (lowest possible value) in all provided particle systems.
            foreach (ParticleSystem particleSystem in particleSystems)
            {
                Assert.IsTrue(Math.Abs(particleSystem.shape.radius - 0.01f) < 0.001f);
            }

            yield break;
        }
        public IEnumerator DeactivateWhenNotActiveTest()
        {
            // Given an inactive valid confetti machine,
            GameObject      machineObject   = Object.Instantiate(Resources.Load <GameObject>(pathToDefaultPrefab));
            ConfettiMachine confettiMachine = machineObject.GetComponent <ConfettiMachine>();

            ParticleSystem[] particleSystems = machineObject.GetComponentsInChildren <ParticleSystem>(true);
            Assert.IsTrue(particleSystems.Length > 0);

            // When I deactivate it,
            confettiMachine.Deactivate();

            // Then the confetti machine is not active and all of its particle systems are deactivated and not playing.
            Assert.IsFalse(confettiMachine.IsActive);

            foreach (ParticleSystem particleSystem in particleSystems)
            {
                Assert.IsFalse(particleSystem.isPlaying);
                Assert.IsFalse(particleSystem.gameObject.activeSelf);
            }

            yield break;
        }
        public IEnumerator ChangeToPositiveEmissionDurationTest()
        {
            // Given a valid confetti machine with particle systems and a new positive duration,
            GameObject      machineObject   = Object.Instantiate(Resources.Load <GameObject>(pathToDefaultPrefab));
            ConfettiMachine confettiMachine = machineObject.GetComponent <ConfettiMachine>();

            ParticleSystem[] particleSystems = machineObject.GetComponentsInChildren <ParticleSystem>(true);
            Assert.IsTrue(particleSystems.Length > 0);

            float newDuration = particleSystems[0].main.duration + confettiMachine.EmissionDuration + 1.47f;

            // When I change the emission duration,
            confettiMachine.ChangeEmissionDuration(newDuration);

            // Then it is accordingly changed in the confetti machine component itself and in all of its particle systems.
            Assert.IsTrue(Math.Abs(confettiMachine.EmissionDuration - newDuration) < 0.001f);

            foreach (ParticleSystem particleSystem in particleSystems)
            {
                Assert.IsTrue(Math.Abs(particleSystem.main.duration - newDuration) < 0.001f);
            }

            yield break;
        }