@Override
  public int hashCode() {
    int result = groupId != null ? groupId.hashCode() : 0;
    result = 31 * result + (artifactId != null ? artifactId.hashCode() : 0);
    result = 31 * result + (version != null ? version.hashCode() : 0);
    return result;
  }
@Override
  public int hashCode()