private HashSet<OperatorSpec> findAllOperatorSpecs() {
    Collection<InputOperatorSpec> inputOperatorSpecs = this.inputOperators.values();
    HashSet<OperatorSpec> operatorSpecs = new HashSet<>();
    for (InputOperatorSpec inputOperatorSpec : inputOperatorSpecs) {
      operatorSpecs.add(inputOperatorSpec);
      doGetOperatorSpecs(inputOperatorSpec, operatorSpecs);
    }
    return operatorSpecs;
  }
Returns a deserialized {@link OperatorSpecGraph} as a copy from this instance of {@link OperatorSpecGraph}
This is used to create per-task instance of {@link OperatorSpecGraph} when instantiating task instances.

@return a copy of this {@link OperatorSpecGraph} object via deserialization
samza-core/src/main/java/org/apache/samza/operators/OperatorSpecGraph.java