def load_css(css_url=None, version='5.2.0'):
        """Load Dropzone's css resources with given version.

        .. versionadded:: 1.4.4

        :param css_url: The CSS url for Dropzone.js.
        :param version: The version of Dropzone.js.
        """
        css_filename = 'dropzone.min.css'
        serve_local = current_app.config['DROPZONE_SERVE_LOCAL']

        if serve_local:
            css = '<link rel="stylesheet" href="%s" type="text/css">\n' % \
                  url_for('dropzone.static', filename=css_filename)
        else:
            css = '<link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/dropzone@%s/dist/min/%s"' \
                  ' type="text/css">\n' % (version, css_filename)

        if css_url:
            css = '<link rel="stylesheet" href="%s" type="text/css">\n' % css_url
        return Markup(css)
Load Dropzone's css resources with given version.

        .. versionadded:: 1.4.4

        :param css_url: The CSS url for Dropzone.js.
        :param version: The version of Dropzone.js.