presto-main/src/main/java/io/prestosql/operator/MultiChannelGroupByHash.java/MultiChannelGroupByHash/addPage
class MultiChannelGroupByHash:    @Override
    public Work<?> addPage(Page page)
    {
        currentPageSizeInBytes = page.getRetainedSizeInBytes();
        if (isRunLengthEncoded(page)) {
            return new AddRunLengthEncodedPageWork(page);
        }
        if (canProcessDictionary(page)) {
            return new AddDictionaryPageWork(page);
        }

        return new AddNonDictionaryPageWork(page);
    }