public function add($key) : void
    {
        Assert::isInstanceOf($key, Key::class);
        parent::add($key);
    }
public function add($key) : void
    {
        Assert::isInstanceOf($key, Key::class);
        parent::add($key);
    }
public function add ( $ key ) : void { Assert :: isInstanceOf ( $ key , Key :: class ) ; parent :: add ( $ key ) ; }
Add a key to the collection

@psalm-suppress MoreSpecificImplementedParamType
@param \SAML2\Certificate\Key $key
@return void

Type hint not possible due to upstream method signature
Add a key to the collection