Function from_children 

pub fn from_children<'a, Message, Theme, Renderer>(
    children: &'a mut [impl Widget<Message, Theme, Renderer>],
    tree: &'a mut Tree,
    layout: Layout,
    renderer: &Renderer,
    viewport: &Rectangle,
    translation: Vector,
    window: Size,
) -> Vec<Element<'a, Message, Theme, Renderer>>
where
    Renderer: Renderer,

Returns the overlays of the given Widget children.

This method will generally only be used by advanced users that are implementing the Widget trait.