The "Set Unset" tool acts similar to the ctx.save() method, by applying changes to the context, and then unsetting after usage.

This allows the switching of a property of the context with set and unset values previously assigned to changed properties are reapplied - essentially wrapping some drawing with context changes.

su = new SetUnset({
    lineWidth: 10
})

// lineWidth == ...
su.set(ctx)
// lineWidth == 10
su.unset(ctx)
// lineWidth == ...

Implement shortcuts:

class Stroke extends SetUnset {
    getOpts() {
        let supported = new Set([
            , "lineWidth"
        ])

        let map = {
            color: 'strokeStyle'
        }
        let functional = {
            dash: 'lineDashKeyApply'
        }
        return [supported, map, functional]
    }
}

st = new Stroke({
    color: 'red'
})