on method
Implementation
void on(LogLevel level, LogListener listener) {
final extsis = _listeners.any((e) => e.$1 == level && e.$2 == listener);
if (extsis) return;
_listeners.add((level, listener));
}
void on(LogLevel level, LogListener listener) {
final extsis = _listeners.any((e) => e.$1 == level && e.$2 == listener);
if (extsis) return;
_listeners.add((level, listener));
}