Function prepareKeys

packages/core/src/Controller.ts:585–591

* Ensure spring objects exist for each defined key, and attach the * `ctrl` to them for observation. * * The queue is expected to contain `createUpdate` results.

(ctrl: Controller<any>, queue: ControllerQueue[number][])

 * The queue is expected to contain `createUpdate` results.
 */
function prepareKeys(ctrl: Controller<any>, queue: ControllerQueue[number][]) {
  each(queue, props => {
    prepareSprings(ctrl.springs, props, key => {
      return createSpring(key, ctrl)
    })
  })
}