docs: private boolean joinCurrentPosition(LookupSource lookupSource, DriverYieldSignal yieldSignal)
      {
          // while we have a position on lookup side to join against...
          while (joinPosition >= 0) {
              if (lookupSource.isJoinPositionEligible(joinPosition, probe.getPosition(), probe.getPage())) {
                  currentProbePositionProducedRow = true;
  
                  pageBuilder.appendRow(probe, lookupSource, joinPosition);
                  joinSourcePositions++;
              }
  
              // get next position on lookup side for this probe row
              joinPosition = lookupSource.getNextJoinPosition(joinPosition, probe.getPosition(), probe.getPage());
  
              if (yieldSignal.isSet() || tryBuildPage()) {
                  return false;
              }
          }
          return true;
      }