in flink-connector-cassandra/src/main/java/org/apache/flink/connector/cassandra/source/split/SplitsGenerator.java [72:83]
public CassandraEnumeratorState prepareSplits() {
final long numSplitsToGenerate = decideOnNumSplits();
final BigInteger increment =
(partitioner.ringSize).divide(new BigInteger(String.valueOf(numSplitsToGenerate)));
final BigInteger startToken = partitioner.minToken;
return new CassandraEnumeratorState(
numSplitsToGenerate,
increment,
startToken,
partitioner.maxToken,
new ArrayDeque<>());
}