log method
Logs a message at the specified level if it meets the current threshold.
@param level The severity level of the message @param message The text to be logged
Implementation
void log(LogLevel level, String message) {
if (level.index >= _currentLevel.index) {
final AnsiPen pen = _getLevelPen(level);
print('${pen('${level.name.capitalize()}:')} $message');
}
}