MatSelect overlayDir now private when updating from Angular 11 to 12. How do I access it now?

[Jeremy]

In Angular 11, in node_modules\@angular\material\select there is a variable:

```

/**

     * Overlay pane containing the options.

     * @deprecated To be turned into a private API.

     * @breaking-change 10.0.0

     * @docs-private

     */

    overlayDir: CdkConnectedOverlay;

```

that in Angular 12 has now been changed to:

```

/** Overlay pane containing the options. */

    protected _overlayDir: CdkConnectedOverlay;

```

This of course breaks all of my usage of `overlayDir`  For example:

```

let selectionOverlay = this.quickFiltersSelect

              .overlayDir as CdkConnectedOverlay;

```

Gives me the TS error:

```Property 'overlayDir' does not exist on type 'MatSelect'```

...Which makes sense. Now it's protected. So I change .overlayDir to ._overlayDir and now get the TS error:

```

Property '_overlayDir' is protected and only accessible within class '_MatSelectBase<C>' and its subclasses.

```

I then imported _MatSelectBase but I am not sure what to replace it with, or if I should be accessing protected properties in this manner. I think `_MatSelectBase` is a generic, so it is looking for `_MatSelectBase<C>` but I am no longer sure I am on the right path.

Can anyone tell me where I have gone wrong, and what the solution might be?

Thank you.