throw new Error("not implemented");
StringBuilder sb = new StringBuilder(); for (int i = 0; i < members.length; ++i) { if (i > 0) sb.append(','); sb.append(members[i][0]); if (members[i][0] != members[i][1]) { sb.append('-'); sb.append(members[i][1]); } } return sb.toString();
  public String toString()  {    throw new Error("not implemented");  }