public void GetVariantPositions(Stream vcfStream, GenomicRange genomicRange)
        {
            if (vcfStream == null)
            {
                _variantPositions = null;
                return;
            }

            vcfStream.Position = Tabix.VirtualPosition.From(InputStartVirtualPosition).BlockOffset;
            _variantPositions  = PreLoadUtilities.GetPositions(vcfStream, genomicRange, SequenceProvider).ToImmutableDictionary();
        }
        public void GetVariantPositions(Stream vcfStream, GenomicRange genomicRange)
        {
            if (vcfStream == null)
            {
                _variantPositions = null;
                return;
            }

            vcfStream.Position = Tabix.VirtualPosition.From(InputStartVirtualPosition).BlockOffset;
            int numPositions;

            Metrics.SaPositionScan.Start();
            (_variantPositions, numPositions) = PreLoadUtilities.GetPositions(vcfStream, genomicRange, SequenceProvider, RefMinorProvider);
            Metrics.ShowSaPositionScanLoad(numPositions);
        }