presto-cassandra/src/main/java/io/prestosql/plugin/cassandra/util/CassandraCqlUtils.java/CassandraCqlUtils/validIdentifier
class CassandraCqlUtils:    private static String validIdentifier(String identifier)
    {
        if (!identifier.equals(identifier.toLowerCase(ENGLISH))) {
            return quoteIdentifier(identifier);
        }

        if (keywords.contains(identifier.toUpperCase(ENGLISH))) {
            return quoteIdentifier(identifier);
        }
        return identifier;
    }