@Deprecated
  public BufferedMutatorParams pool(ExecutorService pool) {
    this.pool = pool;
    return this;
  }
Override the default executor pool defined by the {@code hbase.htable.threads.*} configuration
values.
@deprecated Since 3.0.0-alpha-2, will be removed in 4.0.0. You can not set it anymore.
            BufferedMutator will use Connection's ExecutorService.
hbase-client/src/main/java/org/apache/hadoop/hbase/client/BufferedMutatorParams.java