@Override
  public void flush() {
    if (writeFn != null) {
      writeFn.flush();
    }
  }
A composable asynchronous table implementation that delegates read/write operations
to the underlying table read and write functions.

@param <K> the type of the key in this table
@param <V> the type of the value in this table
@param <U> the type of the update applied to this table
samza-core/src/main/java/org/apache/samza/table/remote/AsyncRemoteTable.java