public function removeAt($at)
    {
        $elements = count($this->blockManagers) - 1;

        $leftPart = array_slice($this->blockManagers, 0 , $at);
        $rightPart = array_slice($this->blockManagers, $at + 1, $elements);

        $this->blockManagers = array_merge($leftPart, $rightPart);

        return array(
            "left" => $leftPart,
            "right" => $rightPart,
        );
    }