merge
fun merge(metaOut: IndexOutput, indexOut: IndexOutput, dataOut: IndexOutput, docMaps: MutableList<MergeState.DocMap>?, readers: MutableList<PointValues>): IORunnable?
More efficient bulk-add for incoming PointValuess. This does a merge sort of the already sorted values and currently only works when numDims==1. This returns -1 if all documents containing dimensional values were deleted.