Crim

      (^void execute [this ^Tuple tuple]
             (let [^RotatingMap pending (.getObject pending)
                   stream-id (.getSourceStreamId tuple)]
               (if (= stream-id Constants/SYSTEM_TICK_STREAM_ID)
                 ; If stream is is system tick, we rotate
                 (.rotate pending)
                 ; Otherwise we let id equal value 0 from the tuple
                 (let [id (.getValue tuple 0)
                       ; grab our output collector
                       ^OutputCollector output-collector (.getObject output-collector)

Crim

package com.pardot.storm.grouping;

import org.apache.storm.generated.GlobalStreamId;
import org.apache.storm.grouping.CustomStreamGrouping;
import org.apache.storm.task.WorkerTopologyContext;

import java.io.Serializable;
import java.util.*;
import java.util.concurrent.atomic.AtomicInteger;