Arquillian, Graphene and PrimeFaces. How to interact with the fileUpload component?

Question

I've a web application with JSF 2.2, PrimeFaces 6.0.

All is working fine, but I don't know in which way I can interact with the fileUpload component coming from Prime Faces.

In which way can I upload a file using Arquillian, Graphene and Drone?

Just for example, here the interaction with some other components, like textItems and dropdowns

    @Test
    @RunAsClient
    public void testCarManufacturersAndModels() {
        Graphene.guardAjax(indexPage.getCarManufacturersDropdown()).selectByVisibleText("Ajax");
        frontendTestComponent.waitForJStoLoad(browser);
        frontendTestComponent.checkSelect(indexPage.getCarModelsDropdown(), 1, true);

        Graphene.guardAjax(indexPage.getContinentsDropdown()).selectByValue("1");
        frontendTestComponent.waitForJStoLoad(browser);
        frontendTestComponent.checkSelect(indexPage.getCountriesDropdown(), 45, true);
    }

The frontendTestComponent is a my class just to avoid to repeat always the same code.

Thank you!