/**
*
*/
public function setFirst(Content2Type $first = null)
{
// the size may vary between 1 and 12 and corresponds to
// bootstrap container col classes
$this->setSize('content-12');
$this->setCollapse(false);
if ($first) {
$first->setBack($this);
$this->next = $first;
$this->back = null;
} else {
$this->next = null;
$this->back = null;
}
}
