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: main.rs
    path of file: ./repos/rustrogueliketutorial/chapter-38-rooms/src
    
    the code of the file until where you have to start completion: extern crate serde;
use rltk::{GameState, Rltk, Point};
use specs::prelude::*;
use specs::saveload::{SimpleMarker, SimpleMarkerAllocator};

mod components;
pub use components::*;
mod map;
pub use map::*;
mod player;
use player::*;
m
    
    fn entities_to_remove_on_level_change(&mut self) -> Vec<Entity> {
        let entities = self.ecs.entities();
        let player = self.ecs.read_storage::<Player>();
        let backpack = self.ecs.read_storage::<InBackpack>();
        let player_entity = self.ecs.fetch::<Entity>();
        let equipped = self.ecs.read_storage::<Equipped>();

        let mut to_delete : Vec<Entity> = Vec::new();
        for entity in entities.join() {
            let mut should_delete = true;

            // Don't delete the player
            let p = player.get(entity);
            if let Some(_p) = p {
                should_delete = false;
            }

            // Don't delete the player's equipment
            let bp = backpack.get(entity);
            if let Some(bp) = bp {
                if bp.owner == *player_entity {
                    should_delete = false;
                }
            }

            let eq = equipped.get(entity);
            if let Some(eq) = eq {
                if eq.owner == *player_entity {
                    should_delete = false;
                }
            }

            if should_delete {
                to_delete.push(entity);
            }
        }

        to_delete
    }