code: void get(Iterable<Key> keys, IOConsumer<Entity> f) throws IOException {
      run(() -> rw.get(toArray(keys, Key.class)).forEachRemaining(IOConsumer.unchecked(f)));
    }
docs: Prefer this method over {@link #get(Iterable)} to avoid gathering large results in a list.
  @see DatastoreReaderWriter#get(Key...)
  @throws IOException if the underlying client throws {@link DatastoreException}
  or if {@code f} throws {@link IOException}.