coffeMachine in func proto

/**
* parent constructor
* @param {array} arg - arguments
*/
function Machine(...arg){
  let _enabled = false;
  let [_power] = arg;
  this.enable = ()=>{_enabled = true};
  this.disable = ()=>{_enabled=false};
  Object.defineProperties(this, {
    "_enabled": {
      get: ()=>{return _enabled;}
    },
    "_power":{
      get:()=>{return _power;}
    }
  })
}

/**
* CoffeeMachine constructor
* @param {integer} power
* @param {integer} capacity
*/
function CoffeeMachine(power, capacity) {
  Machine.apply(this,arguments);
  if (!isFinite(this._power) || !isFinite(capacity)) throw new Error('Power and Capacity mast be a Integer')
  let waterAmount = 0;
  let timerId;
  let self = this;
  let machine_enable = this.enable; //assign parent enablemethod

  // rewrie own method
  this.enable = ()=>{
    machine_enable.call(this);//call parent method enable
    this.run();
  }
  this.run = () => {
    console.log(`Is running: ${this._enabled}`);
    timerId = setTimeout(onReady, getBoilTime());
  }

  this.stop = () => {
    clearTimeout(timerId);
    this.disabled();
    console.log('Stopped!');
  };
  //getter/seter via method
  this.wa = (amount = 0) => {
    if (!amount) return waterAmount;
    waterAmount = amount;
  };

  this.addWater = (addWater)=>{
    let newAmount = waterAmount + addWater;
    if (newAmount<0 || newAmount>capacity) throw new Error("Check water add count");
    else waterAmount = newAmount;
  };
  //getter/setter via property
  Object.defineProperties(this, {
    "waterAmount": {
      get: () => waterAmount,
      set: (amount) => {
        switch (amount) {
          case (amount < 0) :
            throw new Error('Less then 0');
            break;
          case (amount > capacity) :
            throw new Error('More then capacity');
            break;
          default:
            waterAmount = amount;
        }
      }
    }
  });

  let getBoilTime = function () {
    const c = 4200;
    const dT = 80;
    return c * waterAmount * dT / power;
  }; //.bind(this);

  function onReady() {
    console.log('Coffee ready!');
    self.disable();
  }
}