Help me pls

package com.codegym.task.task15.task1505; import javax.print.DocFlavor; import java.util.ArrayList; import java.util.List; public class Solution { public static interface LivingPart { Object containsBones(); } public static class BodyPart implements LivingPart { private String name; public BodyPart(String name) { this.name = name; } public Object containsBones() { return "Yes"; } public String toString() { String visszater = null; containsBones().equals("Yes") ? visszater = name + " contains bones" : visszater = name + " does not contain bones"; } } public static class Finger extends BodyPart { private boolean isArtificial; public Finger(String name, boolean isArtificial) { super(name); this.isArtificial = isArtificial; } public String containsBones() { if (super.containsBones() == "Yes" && !isArtificial) return "Yes"; return "No"; } } public static void main(String[] args) { printlnFingers(); printlnBodyParts(); printlnLivingParts(); } private static void printlnLivingParts() { if(new BodyPart("Hand").containsBones().equals("Yes")) System.out.println("Yes"); else System.out.println("No"); } private static void printlnBodyParts() { List<BodyPart> bodyParts = new ArrayList<BodyPart>(5); bodyParts.add(new BodyPart("Hand")); bodyParts.add(new BodyPart("Leg")); bodyParts.add(new BodyPart("Head")); bodyParts.add(new BodyPart("Body")); System.out.println(bodyParts.toString()); } private static void printlnFingers() { List<Finger> fingers = new ArrayList<Finger>(5); fingers.add(new Finger("Thumb", true)); fingers.add(new Finger("Forefinger", true)); fingers.add(new Finger("Middle finger", true)); fingers.add(new Finger("Ring-finger", true)); fingers.add(new Finger("Pinky", true)); System.out.println(fingers.toString()); } }