presto-raptor-legacy/src/main/java/io/prestosql/plugin/raptor/legacy/util/MetadataUtil.java/MetadataUtil/checkLowerCase
class MetadataUtil:    private static String checkLowerCase(String value, String name)
    {
        if (value == null) {
            throw new NullPointerException(format("%s is null", name));
        }
        checkArgument(value.equals(value.toLowerCase(ENGLISH)), "%s is not lowercase", name);
        return value;
    }