@Override
public int hashCode() {
final int prime = 31;
int result = 1;
result = prime * result + ((first == null) ? 0 : first.hashCode());
result = prime * result + ((second == null) ? 0 : second.hashCode());
return result;
}
@Override
public boolean equals(Object obj) {
if (this == obj) return true;
if (obj == null) return false;
if (getClass() != obj.getClass()) return false;
Pair other = (Pair) obj;
if (first == null) {
if (other.first != null) return false;
} else if (!first.equals(other.first)) return false;
if (second == null) {
if (other.second != null) return false;
} else if (!second.equals(other.second)) return false;
return true;
}