presto-main/src/main/java/io/prestosql/operator/annotations/FunctionsParserHelper.java/FunctionsParserHelper/parseDescription
class FunctionsParserHelper:    public static Optional<String> parseDescription(AnnotatedElement base, AnnotatedElement override)
    {
        Optional<String> overrideDescription = parseDescription(override);
        if (overrideDescription.isPresent()) {
            return overrideDescription;
        }

        return parseDescription(base);
    }