Warning - The value of the field EggBox.boxSize is not used

I am working on Instantiable classes. I have wrote my code on two separate files but I see the following warning on my EggBox file - The value of the field EggBox.boxSize is not used. However the program runs as expected and I still get the input methods for the user.

If I delete the variable int boxSize then I end up with this warning - Multiple markers at this line- Line breakpoint:EggBox [line: 12] - setboxSize(int)- boxSize cannot be resolved or is not a field

This is an exercise of filling in the blanks that I am trying to complete. It is the last piece of code

The eggBoxApp has no error or warnings

import javax.swing.JOptionPane;
public class EggBoxApp{
	public static void main(String[] args){
		//variables
		int eggs;
		int boxSize;
		int numBoxes;
		int leftOverEggs;
		//objects
		EggBox egg;
		egg=new EggBox();
		//inputs
		eggs=Integer.parseInt(JOptionPane.showInputDialog(null,"Enter a number of eggs"));
		boxSize=6;
		//set
		egg.setEggs(eggs);
		egg.setboxSize(boxSize);
		//compute
		egg.computeBoxes();
		egg.computeLeftOver();
		//get
		eggs=egg.getBoxes();
		eggs=egg.getLeftOver();
		//output
		JOptionPane.showMessageDialog(null,"Number of boxes needed "+numBoxes);
		JOptionPane.showMessageDialog(null,"Number of eggs left over "+leftOverEggs);
	}
}

public class EggBox{
	//vars
	private int eggs;
	private int boxSize;
	private int numBoxes;
	private int leftOverEggs;
	//set
	public void setEggs(int eggs){
		this.eggs=eggs;
	}
	public void setboxSize(int boxSize){
		this.boxSize=boxSize;
	}
	//compute
	public void computeBoxes(){
		numBoxes=eggs/6;
	}
	public void computeLeftOver(){
		leftOverEggs=eggs%6;
	}
	//get
	public int getBoxes(){
		return numBoxes;
	}
	public int getLeftOver(){
		return leftOverEggs;
	}
}

public class EggBox{
	//vars
	**** int eggs;
	**** **** boxSize;
	**** **** numBoxes;
	**** **** leftOverEggs;
	//set
	public **** setEggs(int eggs){
		this.eggs=eggs;
	}
	public **** setBoxSize(int ****){
		this.****=****;
	}
	//compute
	public void computeBoxes(){
		numBoxes=eggs/6;
	}
	public void computeLeftover(){
		leftOverEggs=****;
	}
	//get
	public **** getBoxes(){
		return boxes;
	}
	public **** getLeftover(){
		return leftover;
	}
}

I understand it is a warning but I am not sure how to proceed or fix it. Any help explaining this would be great. Thanks

You are setting the value of the attribute boxSize, but after setting it you never use it.

The warning is based on the fact that if you set a variable, you probably intend to use it, right ?

If you just want to make the warning disappear, you could add some getter (like getBoxSize()) that would return the value of your attribute, and call it.