code: public String singleUse(long singerId) {
      // [START singleUse]
      String column = "FirstName";
      Struct row =
          dbClient.singleUse().readRow("Singers", Key.of(singerId), Collections.singleton(column));
      String firstName = row.getString(column);
      // [END singleUse]
      return firstName;
    }
docs: [VARIABLE my_singer_id]