'my-class']) ) ); ?>
'my-class']) ) ); ?>In this example, we are adding a stylesheet from an external URL and using the `Html` helper to render a `div` element with the class `my-class`. Since the stylesheet is defined in an external URL, we don't need to generate any CSS dynamically. Library: PhpTools Overall, PhpTools is a package library that provides a variety of useful tools for PHP developers, including the addCSS function, which allows developers to add CSS stylesheets to their PHP projects. This function can be used with different sources of styles, such as external URLs, local files, and dynamically generated CSS.