Cachearium\CacheAbstract::startCallback PHP Method

    public function startCallback(CacheKey $k, callable $c, array $cparams = [], $lifetime = null)
    {
        $data = $this->start($k, $lifetime);
        if ($data === false) {
            call_user_func_array($c, $cparams);
            $data = $this->end(false);
        }
        return $data;
    }

 protected function _callback(CacheAbstract $cache)
 {
     $base = 'callback';
     $key1 = new CacheKey($base, 1);
     $cache->clean($key1);
     $this->assertEquals(CALLBACKVALUE, $cache->startCallback($key1, 'callbackTester'));
     try {
         $data = $cache->getData($key1);
         $this->assertEquals(CALLBACKVALUE, $data->stringify($cache));
     } catch (Cachearium\Exceptions\NotCachedException $e) {
         $this->fail();
     }
 }