text: 'use strict';
  
  function Thermostat() {
    this.MINTEMP = 10;
    this.MAXTEMP_WITH_PSM = 25;
    this.psm = true;
    this.MAXTEMP_WITHOUT_PSM = 32;
    this.RESET_TEMP = 20;
    this.usage = "";
    this.MEDIUM_USAGE_LIMIT = 18;
    this.HIGH_USAGE_LIMIT = 25;
  }
  Thermostat.prototype.turnOn = function() {
    this.temp = this.RESET_TEMP;
  }
  
  Thermostat.prototype.turnUp = function() {
    if (this.psm && this.temp < this.MAXTEMP_WITH_PSM) {
    this.temp += 1;
  } else if (!this.psm && this.temp < this.MAXTEMP_WITHOUT_PSM){
    this.temp += 1;
    }
  }
  
  Thermostat.prototype.turnDown = function() {
    if (this.temp>this.MINTEMP){
      this.temp -= 1;
    }
  }
  Thermostat.prototype.psmOn = function() {
    this.psm = true
  }
  
  Thermostat.prototype.psmOff = function() {
      this.psm = false
  }
  
  Thermostat.prototype.reset = function(){
    this.temp = this.RESET_TEMP;
  }
  
  Thermostat.prototype.getUsage = function(){
    if (this.temp<  this.MEDIUM_USAGE_LIMIT){
      this.usage ="low";
    } else if (this.temp< this.HIGH_USAGE_LIMIT){
      this.usage ="medium";
    } else {
      this.usage ="high";
    }
  }
  