@Override
  public boolean equals(Object o) {
    if (this == o) {
      return true;
    }
    if (o == null || getClass() != o.getClass()) {
      return false;
    }

    KafkaCheckpointLogKey that = (KafkaCheckpointLogKey) o;

    if (!grouperFactoryClassName.equals(that.grouperFactoryClassName)) {
      return false;
    }
    if (!taskName.equals(that.taskName)) {
      return false;
    }
    return type.equals(that.type);
  }
Two {@link KafkaCheckpointLogKey}s are equal iff their grouperFactory class, taskName and type are equal.
samza-kafka/src/main/java/org/apache/samza/checkpoint/kafka/KafkaCheckpointLogKey.java