added a new class

src/main/java/teetime/stage/DistributedMapCounter.java

+package teetime.stage;
+
+import java.util.HashMap;
+import java.util.Map;
+
+import teetime.framework.AbstractConsumerStage;
+import teetime.framework.OutputPort;
+
+/**
+ * This counts how many of different elements are sent to this stage. Nothing is forwarded.
+ * On termination a Map of T's and counter value is sent to its outputport.
+ *
+ * @author Nelson Tavares de Sousa
+ *
+ * @param <T>
+ */
+public class DistributedMapCounter<T> extends AbstractConsumerStage<T> {
+
+	private final Map<T, Integer> counter = new HashMap<T, Integer>();
+	private final OutputPort<Map<T, Integer>> port = createOutputPort();
+
+	public DistributedMapCounter() {
+
+	}
+
+	@Override
+	protected void execute(final T element) {
+		if (counter.containsKey(element)) {
+			Integer i = counter.get(element);
+			i++;
+			counter.put(element, i);
+		} else {
+			counter.put(element, 0);
+		}
+
+	}
+
+	@Override
+	public void onTerminating() throws Exception {
+		port.send(counter);
+		super.onTerminating();
+	}
+
+}