Creates a Duration object. Duration Accumulators should be named "duration" because the Manager Dashboard looks for this Accumulator name.
Duration elapsedTime(Accumulator accumulatorObject);
Listener listener = new Listener("sampleApp", "4.0");
Container store = listener.lookupContainer("storeName");
Event creations = store.lookupEvent(PCHeventClass.RPC, "document creations");
Accumulator numCreations = creations.lookupAccumulator("number of creations");
Duration elapsedTime = listener.durationFactory(numCreations);
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