Composites to handle reverse anneal

[conta877]

Certain composites do not handle reverse anneal parameters right now (for example the higherordercomposite).

There are multiple ways of dealing with this. Discuss? (10pts)

[arcondello]

One thing that occurs to me would be to add a Initializable (or similar) ABC, similar to Structured. This would signal that the composite/sampler accepts and/or modifies an initial_state kwarg.

[conta877]

both classical solvers and the qpu in principle accepts initial states. I do feel like this should be standard

[arcondello]

Worth noting that dwave-hybrid Runnables all accept an initial state. They also provide a Trait concept that is similar in concept to the dimod ABCs like Structured.

These are different objects with different pros/cons but worth keeping in mind.

[conta877]

ok?