@Override
public boolean equals(Object o) {
if (this == o) return true;
if (o == null || getClass() != o.getClass()) return false;
Pair<?, ?> pair = (Pair<?, ?>) o;
if (x != null ? !x.equals(pair.x) : pair.x != null) return false;
return !(y != null ? !y.equals(pair.y) : pair.y != null);
}
@Override
public int hashCode() {
int result = x != null ? x.hashCode() : 0;
result = 31 * result + (y != null ? y.hashCode() : 0);
return result;
}