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: marshal.rs
    path of file: ./repos/pyo3/src
    
    the code of the file until where you have to start completion: #![cfg(not(Py_LIMITED_API))]

//! Support for the Python `marshal` format.

use crate::ffi_ptr_ext::FfiPtrExt;
use crate::py_result_ext::PyResultExt;
use crate::types::{PyAny, PyBytes};
use crate::{ffi, Bound};
use crate::{AsPyPointer, PyResult, Python};
use std::os::raw::c_int;

/// The current version of the marshal binary format.
pub const VER
    
    fn marshal_roundtrip() {
        Python::with_gil(|py| {
            let dict = PyDict::new_bound(py);
            dict.set_item("aap", "noot").unwrap();
            dict.set_item("mies", "wim").unwrap();
            dict.set_item("zus", "jet").unwrap();

            let pybytes = dumps_bound(py, &dict, VERSION).expect("marshalling failed");
            let deserialized = loads_bound(py, pybytes.as_bytes()).expect("unmarshalling failed");

            assert!(equal(py, &dict, &deserialized));
        });
    }