public function setItemClass($class)
{
if (!class_exists($class)) {
throw new InvalidArgumentException('Item class ' . $class . ' does not exist');
}
$interfaces = class_implements($class, true);
if (!in_array('Stash\\Interfaces\\ItemInterface', $interfaces)) {
throw new \InvalidArgumentException('Item class ' . $class . ' must inherit from \\Stash\\Interfaces\\ItemInterface');
}
$this->itemClass = $class;
return true;
}