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: slab.rs
    path of file: ./repos/logicsim/src/data_structures
    
    the code of the file until where you have to start completion: use std::fmt::{self, Display, Formatter};

/// Transparent type that represents an index into a [Slab].
///
/// used to discourage accessing the [Slab] at arbitrary indexes.
#[derive(Debu
    
    fn test_remove() {
        let mut s = Slab::new();

        assert_eq!(s.remove(SlabIndex(0)), None);

        let index = s.insert(1);
        assert_eq!(s.remove(index), Some(1));

        let new_index = s.insert(2);
        assert_eq!(index, new_index);
        assert_eq!(s.remove(new_index), Some(2));
    }