pub const BAF: &str = "baf";Expand description
Per-cell allele frequency at a called variant locus. Named for what the
matrix measures (B-allele frequency), not for the calling step that chose the
positions: the call set — genotype, GQ, rsid — is snp_sites.parquet /
snp_sites.vcf.gz, and a row here carries none of it, only two read counts.