class ComponentProvider {
 static int _cnt = -1000000;
 static alwaysNewId() => _cnt++;
 static nullId() => null;

 /// Type of the provided Component
 final ComponentType type;

 final CreateComponent createComponent;

 final ComponentProviderId id;

 /**
  * Creates a new [ComponentProvider].
  *
  * The [createComponent] alsways has to create a [Component] that is returned
  * using the factory constructor of that [Component]. Do not return the same
  * instance for multiple calls, because it will be added to [FreeComponents]
  * when it gets removed from the entity on a state change.
  */
 ComponentProvider(Type ctype, this.createComponent, [this.id = nullId]) : type = ComponentTypeManager.getTypeFor(ctype);
}