text: function Thermostat() {
      this.DEFAULT_TEMPERATURE = 20;
      this.temperature = this.DEFAULT_TEMPERATURE;
      this.MAX_TEMP_PSM_ON = 25;
      this.MAX_TEMP_PSM_OFF = 32;
      this.isPowerSaving = true;
      this.MINIMUM_TEMP = 10;
      this.HIGH_USAGE_LIMIT = 25;
      this.LOW_USAGE_LIMIT = 18;
  };
  
  Thermostat.prototype.increaseTemp = function() {
      if (this.temperature >= this._maximumTemperature()) {
          throw new Error("Maximum temperature reached")
      };
  
      this.temperature++
  };
  
  Thermostat.prototype.decreaseTemp = function() {
      if (this.temperature <= this.MINIMUM_TEMP) {
          throw new Error("Minimum temperature reached");
      }
      this.temperature--
  };
  
  Thermostat.prototype.togglePowerSaving = function() {
      this.isPowerSaving = !(this.isPowerSaving != false);
  };
  
  Thermostat.prototype._maximumTemperature = function() {
      return (this.isPowerSaving ? this.MAX_TEMP_PSM_ON : this.MAX_TEMP_PSM_OFF);
  };
  
  Thermostat.prototype.resetToDefault = function() {
      this.temperature = this.DEFAULT_TEMPERATURE;
  };
  
  Thermostat.prototype.energyUsage = function() {
      if (this.temperature < this.LOW_USAGE_LIMIT) {
          return "LOW";
      } else if (this.temperature < this.HIGH_USAGE_LIMIT) {
          return "MEDIUM";
      }
      return "HIGH";
  };
  
  Thermostat.prototype.powerSavingStatus = function() {
      return (this.isPowerSaving ? "ON" : "OFF");
  };