code: public void write(long singerId) {
      // [START write]
      Mutation mutation =
          Mutation.newInsertBuilder("Singer")
              .set("SingerId")
              .to(singerId)
              .set("FirstName")
              .to("Billy")
              .set("LastName")
              .to("Joel")
              .build();
      dbClient.write(Collections.singletonList(mutation));
      // [END write]
    }
docs: [VARIABLE my_singer_id]