pub fn new_with_manager<Css, M>(css: Css, manager: M) -> Result<Self>
    where
        Css: TryInto<StyleSource>,
        crate::Error: From<Css::Error>,
        M: Into<StyleManager>,
    {
        let mgr = manager.into();
        Self::create_impl(css.try_into()?, mgr)
    }
Creates a new style using a custom manager.
packages/stylist/src/global_style.rs