Why is it showing the warning: field is never read: `group`? Is there some option resolve this warning?

I am a newbie at rust programming. Here I was developing a FLTK app using rust. I am getting the following warning.

warning: field is never read: `group`
--> src\views\logo.rs:13:5
   |
13 |     group: fltk::group::Group,
   |     ^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = note: `#[warn(dead_code)]` on by default

Why is it showing the warning: field is never read: group? Is there some option resolve this warning? my code is this:

use fltk::{image::*,
    frame::Frame,
    group::Group,
    enums::Color,
    // enums::Align,
};
use fltk::prelude::*;
use std::fs::read;


pub struct LogoImage {
    group: fltk::group::Group,
    // // button: fltk::button::Button,
    // logo_frame: Frame,
}

impl LogoImage {
    pub fn new(x:i32, y:i32, w:i32, h:i32, label:&'static str) -> LogoImage {
        let mut group = Group::new(x, y, w, h, label);
        group.set_align(fltk::enums::Align::Center);
        group.set_frame(fltk::enums::FrameType::FlatBox);
        group.set_color(fltk::enums::Color::Red);
        // group.set_type(fltk::group::PackType::Horizontal);

        let mut logo_frame = Frame::default()
        // .with_size(w, h)
        .with_size(group.width(), group.height())
        .center_of(&group)
        .with_label("H");
        logo_frame.set_frame(fltk::enums::FrameType::FlatBox);
        logo_frame.set_color(Color::Yellow);

        logo_frame.draw(|f| {
            // let image_data = read("assets\\app_icon.png").unwrap();
            let mut img = PngImage::load("assets\\app_icon.png").unwrap();
            img.scale(f.w(), f.h(), true, true);
            img.draw(f.x(), f.y(), f.w(), f.h());
        });
        
        group.end();
        LogoImage {group} // , logo_frame
    }
    
}

Can some explain me this and give a solution as well (prefer solution in code not in just explanation)?

Make the internals (internal variables) of the struct either intentionally starting with _ (ie., _group) to avoid warning or use pub in front of the internal variable (ie., pub group ...) and use it in another rs file. Answer:

    use fltk::{image::*,
        frame::Frame,
        group::Group,
        enums::Color,
        // enums::Align,
    };
    use fltk::prelude::*;
    use std::fs::read;
    
    
    pub struct LogoImage {
        _group: fltk::group::Group, // or pub group: .......
    }
    
    impl LogoImage {
        pub fn new(x:i32, y:i32, w:i32, h:i32, label:&'static str) -> LogoImage {
            let mut group = Group::new(x, y, w, h, label);
            group.set_align(fltk::enums::Align::Center);
            group.set_frame(fltk::enums::FrameType::FlatBox);
            group.set_color(fltk::enums::Color::Red);
            // group.set_type(fltk::group::PackType::Horizontal);
    
            let mut logo_frame = Frame::default()
            // .with_size(w, h)
            .with_size(group.width(), group.height())
            .center_of(&group)
            .with_label("H");
            logo_frame.set_frame(fltk::enums::FrameType::FlatBox);
            logo_frame.set_color(Color::Yellow);
    
            logo_frame.draw(|f| {
                // let image_data = read("assets\\app_icon.png").unwrap();
                let mut img = PngImage::load("assets\\app_icon.png").unwrap();
                img.scale(f.w(), f.h(), true, true);
                img.draw(f.x(), f.y(), f.w(), f.h());
            });
            
            group.end();
            LogoImage {group} // , logo_frame
        }
        
    }