public ParticleEmitter(ParticleEmitterPrefab prefab)
 {
     System.Diagnostics.Debug.Assert(prefab != null, "The prefab of a particle emitter cannot be null");
     Prefab = prefab;
 }
 public ParticleEmitter(XElement element)
 {
     Prefab = new ParticleEmitterPrefab(element);
 }