public WebElement getFrozenBodyWebElement() {
        return findElement(By.className("ui-datatable-frozenlayout-left")).findElement(By.tagName("tbody"));
    }
Gets the Select All checkbox in the header of the table.

@return the WebElement representing the checkbox
primefaces-selenium/primefaces-selenium-components/src/main/java/org/primefaces/selenium/component/base/AbstractTable.java