else {
// if next operator needs input...
if (next.needsInput()) {
// get an output page from current operator
current.getOperatorContext().startIntervalTimer();
Page page = current.getOutput();
current.getOperatorContext().recordGetOutput(page);
// if we got an output page, add it to the next operator
if (page != null) {
next.getOperatorContext().startIntervalTimer();