createFirstStep
fun <S : AutoCloseable, K2 : WithStream, U : Any> createFirstStep(batchAccumulator: BatchAccumulator<S, StreamKey, DestinationRecordRaw, U>, outputPartitioner: OutputPartitioner<StreamKey, DestinationRecordRaw, K2, U>?, outputQueue: PartitionedQueue<PipelineEvent<K2, U>>?, part: Int, numWorkers: Int, maxNumConcurrentKeys: Int? = null): LoadPipelineStepTask<S, StreamKey, DestinationRecordRaw, K2, U>