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: room_exploder.rs
    path of file: ./repos/rustrogueliketutorial/chapter-64-curses/src/map_builders
    
    the code of the file until where you have to start completion: use super::{MetaMapBuilder, BuilderMap, TileType, paint, Symmetry, Rect};
use rltk::RandomNumberGenerator;

pub struct RoomExploder {}

impl MetaMapBuilder for RoomExploder {
    fn build_map(&mut self, rng: &mut rltk::RandomNumberGenerator, build_data : &mut BuilderMap)  {
        self.build(rng, build_data);
    }
}

impl RoomExploder {
    #[allow(dead_code)]
    pub fn new() -> Box<RoomExploder> {
        Box::new(RoomExploder{})
    }

    fn build(&mut self, rng : &mut RandomNumberGenerator, build_data : &mut Buil
    
    fn build(&mut self, rng : &mut RandomNumberGenerator, build_data : &mut BuilderMap) {
        let rooms : Vec<Rect>;
        if let Some(rooms_builder) = &build_data.rooms {
            rooms = rooms_builder.clone();
        } else {
            panic!("Room Explosions require a builder with room structures");
        }

        for room in rooms.iter() {
            let start = room.center();
            let n_diggers = rng.roll_dice(1, 20)-5;
            if n_diggers > 0 {
                for _i in 0..n_diggers {
                    let mut drunk_x = start.0;
                    let mut drunk_y = start.1;

                    let mut drunk_life = 20;
                    let mut did_something = false;

                    while drunk_life > 0 {
                        let drunk_idx = build_data.map.xy_idx(drunk_x, drunk_y);
                        if build_data.map.tiles[drunk_idx] == TileType::Wall {
                            did_something = true;
                        }
                        paint(&mut build_data.map, Symmetry::None, 1, drunk_x, drunk_y);
                        build_data.map.tiles[drunk_idx] = TileType::DownStairs;

                        let stagger_direction = rng.roll_dice(1, 4);
                        match stagger_direction {
                            1 => { if drunk_x > 2 { drunk_x -= 1; } }
                            2 => { if drunk_x < build_data.map.width-2 { drunk_x += 1; } }
                            3 => { if drunk_y > 2 { drunk_y -=1; } }
                            _ => { if drunk_y < build_data.map.height-2 { drunk_y += 1; } }
                        }

                        drunk_life -= 1;
                    }
                    if did_something {
                        build_data.take_snapshot();
                    }

                    for t in build_data.map.tiles.iter_mut() {
                        if *t == TileType::DownStairs {
                            *t = TileType::Floor;
                        }
                    }
                }
            }
        }
    }