def compose_indexer_with_indexer(countA, indexerA, countB, indexerB):
if _Subset._is_all_slice(indexerA):
return indexerB
if _Subset._is_all_slice(indexerB):
return indexerA
indexA = SnpReader._make_sparray_from_sparray_or_slice(countA, indexerA)
indexB = SnpReader._make_sparray_from_sparray_or_slice(countB, indexerB)
indexAB = indexA[indexB]
return indexAB
