Superstructures

[rcahoon]

Description

Add support for encapsulating Mechanisms into superstructures.

How Has This Been Tested?

Please describe the tests that you ran to verify your changes. Be detailed so that your code reviewer can understand exactly how much and what kinds of testing were done, and which might still be worthwhile to do.

• Unit tests: Units tests for new functionality are included in this PR
• Simulator testing: [Add your description here]
• On-robot bench testing: [Add your description here]
• On-robot field testing: [Add your description here]

[dejabot]

did you debate having superstructures be an attribute of Mechanism vs having Superstructure as a subclass of Mechanism (maybe with the ctor taking the constituent Mechanisms as arguments)? if so, curious about any rationale there. (you've thought about this a lot more - my initial instinct here would be to have Superstructure be a subclass, but I haven't thought through potential gotchas yet...)

[rcahoon]

did you debate having superstructures be an attribute of Mechanism vs having Superstructure as a subclass of Mechanism (maybe with the ctor taking the constituent Mechanisms as arguments)? if so, curious about any rationale there. (you've thought about this a lot more - my initial instinct here would be to have Superstructure be a subclass, but I haven't thought through potential gotchas yet...)

Talked through this offline. We're going to have a Superstructure base class, but do this:

public class Arm extends Superstructure<...> {
    ...

    public Arm() {
        this.shoulder = addMechanism(new Shoulder());
        this.elevator = addMechanism(new Elevator());
        this.wrist = addMechanism(new Wrist());
    }

    ...
}