How to use the gnomad.utils.annotations.fs_from_sb function in gnomad

if "DP" in list(sum_agg_fields) + list(int32_sum_agg_fields):
        logger.warning(
            "`DP` was included in site-level aggregation. This requires a densifying prior to running get_site_info_expr"
        )

    agg_expr = _get_info_agg_expr(
        mt=mt,
        sum_agg_fields=sum_agg_fields,
        int32_sum_agg_fields=int32_sum_agg_fields,
        median_agg_fields=median_agg_fields,
        array_sum_agg_fields=array_sum_agg_fields,
    )

    # Add FS if SB is present
    # This is done outside of _get_info_agg_expr as the behavior is different in site vs allele-specific versions
    agg_expr["FS"] = fs_from_sb(agg_expr["SB"])

    # Run aggregator on non-ref genotypes
    info = hl.agg.filter(
        mt.LGT.is_non_ref(),
        hl.struct(**{k: v for k, v in agg_expr.items() if k != "DP"}),
    )

    # Add DP, computed over both ref and non-ref genotypes, if present
    if "DP" in agg_expr:
        info = info.annotate(DP=agg_expr["DP"])

    return info

                lambda i: fs_from_sb(as_sb_table[0].extend(as_sb_table[i]))
            ),