@Override
  public CompletableFuture<Void> deleteSnapshots(Pattern pattern) {
    return wrap(rawAdmin.deleteSnapshots(pattern));
  }
Just a wrapper of {@link RawAsyncHBaseAdmin}. The difference is that users need to provide a
thread pool when constructing this class, and the callback methods registered to the returned
{@link CompletableFuture} will be executed in this thread pool. So usually it is safe for users
to do anything they want in the callbacks without breaking the rpc framework.
@since 2.0.0
@see RawAsyncHBaseAdmin
@see AsyncConnection#getAdmin(ExecutorService)
@see AsyncConnection#getAdminBuilder(ExecutorService)
hbase-client/src/main/java/org/apache/hadoop/hbase/client/AsyncHBaseAdmin.java