presto-cassandra/src/main/java/io/prestosql/plugin/cassandra/CassandraTokenSplitManager.java/CassandraTokenSplitManager/unwrap
class CassandraTokenSplitManager:    private Set<TokenRange> unwrap(Set<TokenRange> tokenRanges)
    {
        ImmutableSet.Builder<TokenRange> result = ImmutableSet.builder();
        for (TokenRange range : tokenRanges) {
            result.addAll(range.unwrap());
        }
        return result.build();
    }