@Override
    public boolean equals(Object obj) {
        if(this == obj){
            return true;
        }

        if(obj == null){
            return false;
        }

        //instanceof and getClass
        if(obj.getClass() != Worker.class){
            return false;
        }

        Worker other = (Worker) obj;

        return this.id == other.getId() && this.age == other.getAge() &&
                this.name.equals(other.name) && this.start.equals(other.getStart());

    }