String getShardKey(Message message) {
        return getShardKey(message.getTokenTime(), this.modShardPolicy.getMessageShard(message, metadata));
    }
String getShardKey ( Message message ) { return getShardKey ( message . getTokenTime ( ) , this . modShardPolicy . getMessageShard ( message , metadata ) ) ; }
Return the shard for this message
@param message
@return