private void _testFanoutWithPeek(boolean after) throws Exception { Topology t = newTopology(); Graph g = t.graph(); /* -- Filter -- Sink(.) * / * Source -- Peek -- FanOut ---- Modify -- Sink(@) * */ TStream<Integer> d = integers(t, 1, 2, 3); List<Integer> peekedValues = new ArrayList<>(); if (!after) d.peek(tuple -> peekedValues.add(tuple)); TStream<Integer> df = d.filter(tuple -> tuple.intValue() > 0); TStream<Integer> dm = d.modify(tuple -> new Integer(tuple.intValue() + 1)); if (after) d.peek(tuple -> peekedValues.add(tuple)); df.sink(tuple -> System.out.print(".")); dm.sink(tuple -> System.out.print("@")); assertEquals(7, g.getVertices().size()); assertEquals(6, g.getEdges().size()); // Insert counter metrics into all the streams Metrics.counter(t); printGraph(g); assertEquals(10, g.getVertices().size()); assertEquals(9, g.getEdges().size()); }