@Override
  public void stop(ExecutionContext context) throws ExecutorException {
    Iterator<Integer> iter = executions.keySet().iterator();
    while (iter.hasNext()) {
      stopExecution(context, iter.next());
      iter.remove();
    }
    outputData.clear();
  }
Samza implementation of Executor for Samza SQL Shell.
samza-sql-shell/src/main/java/org/apache/samza/sql/client/impl/SamzaExecutor.java