@Override public Call<T> map(AsyncResultSet rs) {
      while (rs.remaining() > 0) {
        accumulator.accept(rs.one(), pendingResults);
      }
      // Return collected results if there are no more pages
      return rs.getExecutionInfo().getPagingState() == null && !rs.hasMorePages()
        ? Call.create(finisher.apply(pendingResults))
        : new FetchMoreResults(rs).flatMap(this);
    }
Iterates through the rows in each page, flatmapping on more results until exhausted
zipkin-storage/cassandra/src/main/java/zipkin2/storage/cassandra/internal/call/AccumulateAllResults.java