public static NormalizedParameters normalize(String msg, Object[] arguments, Throwable t) {

        if (t != null) {
            return new NormalizedParameters(msg, arguments, t);
        }

        if (arguments == null || arguments.length == 0) {
            return new NormalizedParameters(msg, arguments, t);
        }

        Throwable throwableCandidate = NormalizedParameters.getThrowableCandidate(arguments);
        if (throwableCandidate != null) {
            Object[] trimmedArguments = MessageFormatter.trimmedCopy(arguments);
            return new NormalizedParameters(msg, trimmedArguments, throwableCandidate);
        } else {
            return new NormalizedParameters(msg, arguments);
        }

    }
This method serves to normalize logging call invocation parameters.

More specifically, if a throwable argument is not supplied directly, it
attempts to extract it from the argument array.
slf4j-api/src/main/java/org/slf4j/helpers/NormalizedParameters.java