presto-kafka/src/main/java/io/prestosql/plugin/kafka/KafkaRecordSetProvider.java/KafkaRecordSetProvider/getDecoderParameters
class KafkaRecordSetProvider:    private Map<String, String> getDecoderParameters(Optional<String> dataSchema)
    {
        ImmutableMap.Builder<String, String> parameters = ImmutableMap.builder();
        dataSchema.ifPresent(schema -> parameters.put("dataSchema", schema));
        return parameters.build();
    }