presto-main/src/main/java/io/prestosql/metadata/MetadataUtil.java/MetadataUtil/checkLowerCase
class MetadataUtil:    public 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: %s", name, value);
        return value;
    }