pub fn level_from_bracketed(s: &str) -> Option<LogLevel>Expand description
The LogLevel inside a header’s [LEVEL] field, or None when the
brackets are missing or hold no level the switch knows.
LogLevel’s own FromStr is the switch’s case-sensitive LEVELS[] lookup
and the log spells the level in upper case, so the names are compared here
instead: folding the name would allocate on every header line.