docs: private static final String toStringPuIds(String desc, JPAPuId[] puids)
      {
          StringBuilder sbuf = new StringBuilder(desc);
          sbuf.append('\n');
          for (JPAPuId puid : puids)
          {
              sbuf.append("   ")
                              .append(puid)
                              .append('\n');
          }
          return sbuf.toString();
      }