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: flex.rs
    path of file: ./repos/ratatui/examples
    
    the code of the file until where you have to start completion: //! # [Ratatui] Flex example
//!
//! The latest version of this example is available in the [examples] folder in the repository.
//!
//! Please note that the examples are designed to be run against the `main` branc
    
    fn illustration(constraint: Constraint, width: u16) -> impl Widget {
        let main_color = color_for_constraint(constraint);
        let fg_color = Color::White;
        let title = format!("{constraint}");
        let content = format!("{width} px");
        let text = format!("{title}\n{content}");
        let block = Block::bordered()
            .border_set(symbols::border::QUADRANT_OUTSIDE)
            .border_style(Style::reset().fg(main_color).reversed())
            .style(Style::default().fg(fg_color).bg(main_color));
        Paragraph::new(text).centered().block(block)
    }