@Override
    public TimestampType timestampType() {
        return (attributes() & TIMESTAMP_TYPE_MASK) == 0 ? TimestampType.CREATE_TIME : TimestampType.LOG_APPEND_TIME;
    }
Gets the base timestamp of the batch which is used to calculate the record timestamps from the deltas.

@return The base timestamp
clients/src/main/java/org/apache/kafka/common/record/DefaultRecordBatch.java