SonarQube: Invoke method(s) only conditionally

The call to us.toString() is redundant, toString() method will be called regardless the configured log level. You should pass only us as an argument to info without an if statement.

logger.info("Log this: {}", us);

As stated at the comments of the question, another working answer is:

if(logger.isInfoEnabled() && us != null){
    logger.info("Log this: {}", us.toString());
}