Properties the declarative way

getter-setter-ideal.js

const $frequency = Symbol.for("Overthruster:frequency")

export class Overthruster
{
  constructor({frequency}={}){
    this[$frequency]= frequency
  }
  get frequency(){
    return this[ $frequency]
  }
}

// Things I like about this approach:
// * Object.getOwnPropertyDescriptor(Overthruster.prototype.frequency) returns something! There's some reflection!
// * Getter/setters can be extended using .super.
// * The underlying state is accessible, which to me is a major positive. User beware, but it's obvious you're going slightly far afield.