<?php

$mcache = \G4\Mcache\McacheFactory::createInstance($driverName, $options, $prefix);

$key = \G4\RussianDoll\Key('posts');
$key
    ->addVariablePart($perPage)
    ->addVariablePart($page);

$russianDoll = new \G4\RussianDoll\RussianDoll($mcache);
$russianDoll->setKey($key);

// get data from cache
$posts = $russianDoll->fetch();

// write data to cache
$russianDoll->write($posts);

// invalidate cache entry
$russianDoll->expire();