/** {@inheritDoc} */
public void setNextReader(LeafReaderContext ctx) throws IOException {
if (valueSource == null) {
// first time we've collected local values, get the right ValueSource
valueSource = (null == ft) ? statsField.getValueSource() : ft.getValueSource(sf, null);
vsContext = ValueSource.newContext(statsField.getSearcher());
}
values = valueSource.getValues(vsContext, ctx);
}
