Tuple.java

public class Tuple {

    public Integer first;
    public Integer second;

    public Tuple() {
    }

    public Tuple(Integer first, Integer second) {
        this.first = first;
        this.second = second;
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (o == null || getClass() != o.getClass()) return false;

        Tuple that = (Tuple) o;

        if (first != null ? !first.equals(that.first) : that.first != null) return false;
        return second != null ? second.equals(that.second) : that.second == null;
    }

}