如何在equals函数的子类方法中调用受保护的变量？

public class ParentClass {
    protected int protectedVariable;

    public ParentClass(int protectedVariable) {
        this.protectedVariable = protectedVariable;
    }

    // equals方法的实现
    @Override
    public boolean equals(Object obj) {
        if (this == obj) {
            return true;
        }
        if (obj == null || getClass() != obj.getClass()) {
            return false;
        }
        ParentClass other = (ParentClass) obj;
        return protectedVariable == other.protectedVariable;
    }
}

public class ChildClass extends ParentClass {
    private int privateVariable;

    public ChildClass(int protectedVariable, int privateVariable) {
        super(protectedVariable);
        this.privateVariable = privateVariable;
    }

    // 子类中重写equals方法
    @Override
    public boolean equals(Object obj) {
        if (!super.equals(obj)) {
            return false;
        }
        ChildClass other = (ChildClass) obj;
        return privateVariable == other.privateVariable;
    }
}