Zend Framework 2. Zend\Di setter injection.

class A
{
    protected $username;
    
    protected $password;
    
    public function __construct($username, $password)
    {
        $this->username = $username;
        $this->password = $password;
    }
}

class B
{
    protected $a = null;
    
    public function setA(A $a)
    {
        $this->a = $a;
    }
}

class C
{
    protected $b = null;
    
    public function __construct(B $b)
    {
        $this->b = $b;
    }
}

$di = new \Zend\Di\Di;
$options = array(
    'definition' => array(
        'class' => array(
            'Application\Service\B' => array(
                'setA' => array(
                    'required' => true
                )
            )
        )
    )
);
$config = new \Zend\Di\Config($options);
$di->configure($config);
$di->instanceManager()
            ->setParameters('Application\Service\A', array(
    'username' => 'leon',
    'password' => 'sf32KLjldos'
));

$c = $di->get('Application\Service\C');

var_dump($c);

object(Application\Service\C)[246]
  protected 'b' => 
    object(Application\Service\B)[242]
      protected 'a' => 
        object(Application\Service\A)[244]
          protected 'username' => string 'leon' (length=4)
          protected 'password' => string 'sf32KLjldos' (length=11)