presto-phoenix/src/main/java/io/prestosql/plugin/phoenix/PhoenixTableProperties.java/PhoenixTableProperties/getDisableWal
class PhoenixTableProperties:    public static Optional<Boolean> getDisableWal(Map<String, Object> tableProperties)
    {
        requireNonNull(tableProperties);

        Boolean value = (Boolean) tableProperties.get(DISABLE_WAL);
        if (value == null) {
            return Optional.empty();
        }
        return Optional.of(value);
    }