code: private static void appendAltIDs(StringBuilder logMsg, String[] altIDs) {
          logMsg.append(", altIDs: ");
          if (altIDs == null) {
              logMsg.append("null");
          } else {
              for (String altID : altIDs) {
                  logMsg.append("'").append(altID).append("'");
              }
          }
      }
docs: Appends alt IDs to the log message.