@Override
  public int hashCode() {
    int result = first != null ? first.hashCode() : 0;
    result = 31 * result + (second != null ? second.hashCode() : 0);
    return result;
  }
An immutable pair of elements.

@author Peter Niederwieser
spock-core/src/main/java/org/spockframework/util/Pair.java