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: tests.rs
    path of file: ./repos/specs/src/storage
    
    the code of the file until where you have to start completion: use std::any::Any;

use super::*;
use crate::world::{Component, Entity, Generation, Index, WorldExt};
use shred::World;
use std::mem::MaybeUninit;

// Make tests finish in reasonable time with miri
const ITERATIONS: u32 = if cfg!(miri) { 100 } else { 1000 };

fn create<T: Component>(world: &mut World) -> WriteStorage<T
    
    fn vec_arc() {
        use std::sync::Arc;

        #[derive(Debug)]
        struct A(Arc<()>);

        let mut storage = VecStorage::<A>::default();
        let mut bitset = BitSet::new();

        unsafe {
            for i in (0..200).filter(|i| i % 2 != 0) {
                storage.insert(i, A(Arc::new(())));
                bitset.add(i);
            }
            storage.clean(&bitset);
        }
    }