public WebElement getAdvancedCancelButton() {
        return findElement(By.cssSelector(".ui-fileupload-buttonbar button.ui-fileupload-cancel"));
    }
Gets the Cancel button of the widget.
The button is only rendered in advanced mode.
@return the widget's cancel button
primefaces-selenium/primefaces-selenium-components/src/main/java/org/primefaces/selenium/component/FileUpload.java