Function learn_record 

pub fn learn_record(
    ballots: &[(String, String)],
    outcome: &str,
    records: &BTreeMap<String, Standing>,
    about: &[String],
) -> Result<(Vec<Trust>, BTreeMap<String, Standing>)>

Learn from an outcome by the record: each voter’s hits and misses so far, this outcome added, give its accuracy with one of each smoothed in, and the rows are the log odds of that scaled to the best voter at one (calibration_weights). Measured against multiplicative shrinking (Hedge) on voters of known accuracy, the record reaches the batch calibration and the shrink does not: a voter is weighed by what it got right, not by how many times it has been punished. Rows are complete over the voters and scoped to about.

Errors

No outcome, or fewer than two voters.