Data Classes AccumulateException Class1 getCollection * return Class2 isUpdatable return update return Class2Iterator iterate return * collection next return done return Class3 accumulate x Exception GeneralException nestedException GetException UpdateException private StructuredNodes target bodyOutput target decider target 1 result 1 1 1 1 parallel * collection target x target decider target target 1 1 1 1 loopVariableInput 1 1 value result 1 1 1 1 1