You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: canvas.rs
    path of file: ./repos/Fyrox/fyrox-ui/src
    
    the code of the file until where you have to start completion: //! Canvas widget allows its children to have an arbitrary position on an imaginable infinite plane, it also
//! gives the children constraints of infinite size, which forces them to take all the desired size. See
//! [`Canvas`] docs for more info and usage examples.

#![warn(missing_docs)
    
    fn arrange_override(&self, ui: &UserInterface, final_size: Vector2<f32>) -> Vector2<f32> {
        scope_profile!();

        for &child_handle in self.widget.children() {
            let child = ui.nodes.borrow(child_handle);
            ui.arrange_node(
                child_handle,
                &Rect::new(
                    child.desired_local_position().x,
                    child.desired_local_position().y,
                    child.desired_size().x,
                    child.desired_size().y,
                ),
            );
        }

        final_size
    }