in lib/src/logger.dart [121:132]
set level(Level? value) {
if (!hierarchicalLoggingEnabled && parent != null) {
throw UnsupportedError(
'Please set "hierarchicalLoggingEnabled" to true if you want to '
'change the level on a non-root logger.');
}
if (parent == null && value == null) {
throw UnsupportedError(
'Cannot set the level to `null` on a logger with no parent.');
}
_level = value;
}