InputOperatorSpec getInputOperator(String inputStreamId) {
    if (!inEdges.containsKey(inputStreamId)) {
      return null;
    }
    return appDesc.getInputOperators().get(inputStreamId);
  }
Generate the configs for a job
@param executionPlanJson JSON representation of the execution plan
@return config of the job
samza-core/src/main/java/org/apache/samza/execution/JobNode.java