Comment 4 for bug 1209713

I understand, i am saying i don't like using Class<T> parameters to tell which algorithm to use as it makes extending the library difficult. Yes user doesn't have to worry about creating a new instance, but severely restricts capability to plugin custom implementations. I prefer instance over Class because if someone wants to create a custom type, they don't have to modify engine. For example, if i want to test with a CustomJarrod that extends Jarrod which needs more initialization parameters than that are used when instance
is created by library, then user need to modify engine as well which is not desired. Class type also introduces more non-type safe pitfalls.