fix: deleted methods that I was not using in my test

Author: Dasiame

lesson_16/objects/objects_app/src/main/java/com/codedifferently/lesson16/SmartPhone/SmartPhone.java

@@ -29,23 +29,13 @@ public int getBatteryPercentage() {
     return batteryPercentage;
   }
 
-  public void setSmartPhoneBatteryIncrease(int chargeBatteryAmount) {
-    // loop
-  }
-
-  public void chargeSmartPhone() {}
-
-  public void setSmartPhonePower() {}
-
   public void setSmartPhoneBatteryPercentage(int currentBatteryPercentage) {
     if (currentBatteryPercentage < 0 || currentBatteryPercentage > 100) {
       throw new IllegalArgumentException("Battery percentage must be in between 0 and 100.");
     }
     this.batteryPercentage = currentBatteryPercentage;
   }
 
-  public void addSmartPhoneApps(String App) {}
-
   public String getSmartPhoneApps() {
     var smartPhoneApps = "";
     for (String s : apps) {
@@ -58,10 +48,6 @@ public void removeSmartPhoneApps(String App) {
     apps.remove(App);
   }
 
-  public void currentSmartPhoneVolume() {}
-
-  public void addSmartPhoneVolume() {}
-
   public int getSmartPhoneVolume() {
     return 5;
   }