public void injectElement(InputT value, Instant timestamp) throws Exception {
   Collection<W> windows =
       windowFn.assignWindows(
           new TriggerTester.StubAssignContext<W>(
               windowFn, value, timestamp, Arrays.asList(GlobalWindow.INSTANCE)));
   logInteraction(
       "Element %s at time %d put in windows %s", value, timestamp.getMillis(), windows);
   runner.processElement(WindowedValue.of(value, timestamp, windows, PaneInfo.NO_FIRING));
 }
  protected <T> WindowedValue<T> makeWindowedValue(
      T output, Instant timestamp, Collection<? extends BoundedWindow> windows, PaneInfo pane) {
    final Instant inputTimestamp = timestamp;
    final WindowFn windowFn = windowingStrategy.getWindowFn();

    if (timestamp == null) {
      timestamp = BoundedWindow.TIMESTAMP_MIN_VALUE;
    }

    if (windows == null) {
      try {
        windows =
            windowFn.assignWindows(
                windowFn.new AssignContext() {
                  @Override
                  public Object element() {
                    throw new UnsupportedOperationException(
                        "WindowFn attempted to access input element when none was available"); // TODO: 12/16/15 aljoscha's comment in slack
                  }

                  @Override
                  public Instant timestamp() {
                    if (inputTimestamp == null) {
                      throw new UnsupportedOperationException(
                          "WindowFn attempted to access input timestamp when none was available");
                    }
                    return inputTimestamp;
                  }

                  @Override
                  public Collection<? extends BoundedWindow> windows() {
                    throw new UnsupportedOperationException(
                        "WindowFn attempted to access input windows when none were available");
                  }
                });
      } catch (Exception e) {
        Throwables.propagateIfInstanceOf(e, UserCodeException.class);
        throw new UserCodeException(e);
      }
    }

    return WindowedValue.of(output, timestamp, windows, pane);
  }
 public void fireTimer(W window, Instant timestamp, TimeDomain domain) {
   runner.onTimer(
       TimerData.of(StateNamespaces.window(windowFn.windowCoder(), window), timestamp, domain));
 }
 private StateNamespace windowNamespace(W window) {
   return StateNamespaces.window(windowFn.windowCoder(), window);
 }
  @Override
  public void processElement(ProcessContext c) throws Exception {
    final K key = c.element().getKey();
    Iterator<WindowedValue<InputT>> iterator = c.element().getValue().iterator();

    final PriorityQueue<W> liveWindows =
        new PriorityQueue<>(
            11,
            new Comparator<BoundedWindow>() {
              @Override
              public int compare(BoundedWindow w1, BoundedWindow w2) {
                return Long.signum(w1.maxTimestamp().getMillis() - w2.maxTimestamp().getMillis());
              }
            });

    final Map<W, AccumT> accumulators = Maps.newHashMap();
    final Map<W, Instant> minTimestamps = Maps.newHashMap();

    WindowFn<Object, W>.MergeContext mergeContext =
        new CombiningMergeContext() {
          @Override
          public Collection<W> windows() {
            return liveWindows;
          }

          @Override
          public void merge(Collection<W> toBeMerged, W mergeResult) throws Exception {
            List<AccumT> accumsToBeMerged = new ArrayList<>(toBeMerged.size());
            Instant minTimestamp = null;
            for (W window : toBeMerged) {
              accumsToBeMerged.add(accumulators.remove(window));

              Instant timestampToBeMerged = minTimestamps.remove(window);
              if (minTimestamp == null
                  || (timestampToBeMerged != null && timestampToBeMerged.isBefore(minTimestamp))) {
                minTimestamp = timestampToBeMerged;
              }
            }
            liveWindows.removeAll(toBeMerged);

            minTimestamps.put(mergeResult, minTimestamp);
            liveWindows.add(mergeResult);
            accumulators.put(mergeResult, combineFn.mergeAccumulators(key, accumsToBeMerged));
          }
        };

    while (iterator.hasNext()) {
      WindowedValue<InputT> e = iterator.next();

      @SuppressWarnings("unchecked")
      Collection<W> windows = (Collection<W>) e.getWindows();
      for (W w : windows) {
        Instant timestamp = minTimestamps.get(w);
        if (timestamp == null || timestamp.compareTo(e.getTimestamp()) > 0) {
          minTimestamps.put(w, e.getTimestamp());
        } else {
          minTimestamps.put(w, timestamp);
        }

        AccumT accum = accumulators.get(w);
        checkState((timestamp == null && accum == null) || (timestamp != null && accum != null));
        if (accum == null) {
          accum = combineFn.createAccumulator(key);
          liveWindows.add(w);
        }
        accum = combineFn.addInput(key, accum, e.getValue());
        accumulators.put(w, accum);
      }

      windowFn.mergeWindows(mergeContext);

      while (!liveWindows.isEmpty()
          && liveWindows.peek().maxTimestamp().isBefore(e.getTimestamp())) {
        closeWindow(key, liveWindows.poll(), accumulators, minTimestamps, c);
      }
    }

    // To have gotten here, we've either not had any elements added, or we've only run merge
    // and then closed windows. We don't need to retry merging.
    while (!liveWindows.isEmpty()) {
      closeWindow(key, liveWindows.poll(), accumulators, minTimestamps, c);
    }
  }