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: lib.rs
    path of file: ./repos/wasmtime/crates/wit-bindgen/src
    
    the code of the file until where you have to start completion: use crate::rust::{to_rust_ident, to_rust_upper_camel_case, RustGenerator, TypeMode};
use crate::types::{TypeInfo, Types};
use anyhow::{anyhow, bail, Context};
use heck::*;
use indexmap::{IndexMap, IndexSet};
use std::collections::{BTreeMap, HashMap, HashSet};
use std::fmt::Write as _;
use std::io::{Read, Write};
use std::mem;
use std::process::{Command, Stdio};
use wit_parser::*;

macro_rules! uwrite {
    ($dst:expr, $($arg:tt)*) => {
        write!($dst, $($arg)*).unwrap()
    };
}

macro_rules! uwriteln {
    ($dst:expr, $($arg:tt)*) => {
        writeln!($dst, $($arg)*).unwrap()
    };
}

mod rust;
mod source;
mod types;
use source::Source;

#[derive(Clone)]
enum InterfaceName {
    /// This interface was remapped using `with` to some other Rust code.
    Remapped {
        name_at_root: String,
        local_path: Vec<Stri
    
    fn generate(&mut self, resolve: &Resolve, id: WorldId) -> String {
        self.types.analyze(resolve, id);
        for (i, te) in self.opts.trappable_error_type.iter().enumerate() {
            let id = resolve_type_in_package(resolve, &te.wit_path)
                .context(format!("resolving {:?}", te))
                .unwrap();
            let name = format!("_TrappableError{i}");
            uwriteln!(self.src, "type {name} = {};", te.rust_type_name);
            let prev = self.trappable_errors.insert(id, name);
            assert!(prev.is_none());
        }

        let world = &resolve.worlds[id];
        for (name, import) in world.imports.iter() {
            if !self.opts.only_interfaces || matches!(import, WorldItem::Interface(_)) {
                self.import(resolve, id, name, import);
            }
        }

        for (name, export) in world.exports.iter() {
            if !self.opts.only_interfaces || matches!(export, WorldItem::Interface(_)) {
                self.export(resolve, name, export);
            }
        }
        self.finish(resolve, id)
    }