public static Builder forReplica(short allowedVersion, int replicaId) {
            return new Builder((short) 0, allowedVersion, replicaId, IsolationLevel.READ_UNCOMMITTED);
        }
It is used to represent the earliest message stored in the local log which is also called the local-log-start-offset
clients/src/main/java/org/apache/kafka/common/requests/ListOffsetsRequest.java