presto-main/src/main/java/io/prestosql/operator/PagesIndex.java/PagesIndex/appendTo
class PagesIndex:    public void appendTo(int channel, int position, BlockBuilder output)
    {
        long pageAddress = valueAddresses.getLong(position);

        Type type = types.get(channel);
        Block block = channels[channel].get(decodeSliceIndex(pageAddress));
        int blockPosition = decodePosition(pageAddress);
        type.appendTo(block, blockPosition, output);
    }