How to document the type of a variable in a derived class in PHP?

Question

PHP

Good afternoon!
Faced the following problem.
There is a parent class, for example IterableCollection - an iterator that implements the Iterator interface. This class has the $items property, which is an array of some elements (for the IterableCollection class, it does not matter what these elements are).

class IterableCollection implements \Iterator
{
    /**
     * @var mixed[]
     */
    protected $items = [];

    ...
}

There is a SomeCollection class that inherits from the IterableCollection class. This class is a collection of objects of the SomeClass class, and the protected array $items contains the elements of the SomeClass class.
Next, I want to take some element from the $items protected variable in the derived class, but it turns out (SUDDENLY) that this element is rendered by phpStorm as mixed .

class SomeCollection extends IterableCollection
{
    public function doSomeWork()
    {
        $this->items[0]->someMethod();
    }
    ...
}

The problem is that when I call the someMethod method on the $this->items[0] object, PhpStorm doesn't understand that $this->items[0] is an object of the SomeClass class. There is nothing surprising in this, because it is not declared anywhere.
Question: Is there a way using phpDoc to determine that in the SomeCollection class the $items variable is not mixed[] , but SomeClass[] ?
Interested in the way to do this using phpDoc , and not in any way overriding this property in the derived class.
Thank you.
UPD.
If the parent class does not specify

/**
     * @var mixed[]
     */
    protected $items = [];
}

a

/**
     * @var array
     */
    protected $items = [];
}

then the way

/**
 * @property SomeClass[] $items
 */
class SomeCollection extends IterableCollection {
    ...
}

really works.
BUT.
In this case, the $items property is considered magic and public, and phpStorm now sees it even outside the class, which is wrong.

Answer 1

Obviously, in the absence of generic programming tools (generics) in PHP, it is impossible to do this without crutches (copying code, copying phpDocs, assigning the $items property to magic and public ones, etc.).

Answer 2

class SomeCollection extends IterableCollection
{
    /**
     * @var SomeClass[] $items
     */
    ...
    public function doSomeWork()
    {
        $this->items[0]->someMethod();
    }
    ...
}

Something like this

Answer 3

Very sudden indeed :)

/**
* @var mixed[]
*/
protected $items = [];

Here it is:

/**
 * @property SomeClass[] $items
 */
class SomeCollection extends IterableCollection
// ...

Another option:

public function doSomeWork()
{
    /** @var SomeClass[] $items */
    $items =  $this->items;

    $items[0]->someMethod();
}

And another option:

/**
 * @return SomeClass[]
 */
protected function getItems ()
{
    return $this->items;
}
 
public function doSomeWork()
{
    $this->getItems()[0]->someMethod();
}

Answer 4

another option with re-defining the property with the correct phpDoc

class SomeCollection extends IterableCollection
{
    /**
     * @var SomeClass[]
     */
    protected $items = [];

    public function doSomeWork()
    {
        $this->items[0]->someMethod();
    }
    ...
}