+GtkCssValue * _gtk_css_font_size_value_new (GtkCssFontSize size);
+GtkCssValue * _gtk_css_font_size_value_try_parse (GtkCssParser *parser);
+GtkCssFontSize _gtk_css_font_size_value_get (const GtkCssValue *value);
+double _gtk_css_font_size_get_default (GtkStyleProviderPrivate *provider);
+