/**
* Sets a helper.
*
* @param HelperInterface $helper The helper instance
* @param string $alias An alias
*/
public function set(HelperInterface $helper, $alias = null)
{
$this->helpers[$helper->getName()] = $helper;
if (null !== $alias) {
$this->helpers[$alias] = $helper;
}
$helper->setHelperSet($this);
}
