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: container.rs
    path of file: ./repos/iced/widget/src
    
    the code of the file until where you have to start completion: //! Decorate content and apply alignment.
use crate::core::alignment::{self, Alignment};
use crate::core::event::{self, Event};
use crate::core::gradient::{self, Gradient};
use crate::core::layout;
use crate::core::mouse;
use crate::core::overlay;
use crate::core::renderer;
use crate::core::widget::tree::{self, Tree};
use crate::core::widget::{self, Operation};
use crate::core::{
    Background, Border, Clipboard, Color, Element, Layout, Length, Padding,
    Pixels, Point, Rectangle, Shadow, Shell, Size, Theme, Vector, Widget,
};
use crate::runtime::Command;

/// An element decorating some content.
///
/// It is normal
    
pub fn visible_bounds(id: Id) -> Command<Option<Rectangle>> {
    struct VisibleBounds {
        target: widget::Id,
        depth: usize,
        scrollables: Vec<(Vector, Rectangle, usize)>,
        bounds: Option<Rectangle>,
    }

    impl Operation<Option<Rectangle>> for VisibleBounds {
        fn scrollable(
            &mut self,
            _state: &mut dyn widget::operation::Scrollable,
            _id: Option<&widget::Id>,
            bounds: Rectangle,
            translation: Vector,
        ) {
            match self.scrollables.last() {
                Some((last_translation, last_viewport, _depth)) => {
                    let viewport = last_viewport
                        .intersection(&(bounds - *last_translation))
                        .unwrap_or(Rectangle::new(Point::ORIGIN, Size::ZERO));

                    self.scrollables.push((
                        translation + *last_translation,
                        viewport,
                        self.depth,
                    ));
                }
                None => {
                    self.scrollables.push((translation, bounds, self.depth));
                }
            }
        }

        fn container(
            &mut self,
            id: Option<&widget::Id>,
            bounds: Rectangle,
            operate_on_children: &mut dyn FnMut(
                &mut dyn Operation<Option<Rectangle>>,
            ),
        ) {
            if self.bounds.is_some() {
                return;
            }

            if id == Some(&self.target) {
                match self.scrollables.last() {
                    Some((translation, viewport, _)) => {
                        self.bounds =
                            viewport.intersection(&(bounds - *translation));
                    }
                    None => {
                        self.bounds = Some(bounds);
                    }
                }

                return;
            }

            self.depth += 1;

            operate_on_children(self);

            self.depth -= 1;

            match self.scrollables.last() {
                Some((_, _, depth)) if self.depth == *depth => {
                    let _ = self.scrollables.pop();
                }
                _ => {}
            }
        }

        fn finish(&self) -> widget::operation::Outcome<Option<Rectangle>> {
            widget::operation::Outcome::Some(self.bounds)
        }
    }

    Command::widget(VisibleBounds {
        target: id.into(),
        depth: 0,
        scrollables: Vec::new(),
        bounds: None,
    })
}