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: app.rs
    path of file: ./repos/CaptfEncoder/CaptfEncoder-V3/main/src/apps
    
    the code of the file until where you have to start completion: use std::process;

use fltk::{
    app, dialog,
    enums::{Color, Event, FrameType},
    group::*,
    image::*,   
    prelude::*,
    window::*,
};

use fltk_theme::{color_themes, ColorTheme};

use webbrowser;

use crate::apps::AssetRes;

use crate::apps::extensions::*;
use crate::apps::scripts::*;

use crate::apps::message::Message;
use crate::apps::theme;

use crate::apps::widgets::{
    WgtAboutDialog, WgtBarEnd, WgtBarMid, WgtBarStart, WgtCheckUpdateDialog, WgtClosableTab,
    WgtMenuBar, WgtScriptRunner, WgtSearch, WgtSysteminfoDialog, Wgt
    
    fn create_extension(&mut self, id: String) {
        let extension = self.extension_manager.get_extension(&id);

        if let Some(extension) = extension {
            let label = extension.label.clone();

            let mut grp = Group::new(
                self.tabs.tab_grps.x(),
                self.tabs.tab_grps.y(),
                self.tabs.tab_grps.w(),
                self.tabs.tab_grps.h(),
                "",
            );
            let component_fn = extension.component_fn;
            let component = component_fn().unwrap();
            component.render(&grp);
            self.tabs.add(&mut grp, label.as_str());
            self.tab_count += 1;
        }
    }