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: registered.rs
    path of file: ./repos/glommio/glommio/src/iou/registrar
    
    the code of the file until where you have to start completion: use std::{
    io,
    ops::*,
    os::unix::io::{AsRawFd, RawFd},
};

use crate::{iou::sqe::SQE, uring_sys};

pub const PLACEHOLDER_FD: RawFd = -1;

/// A member of the kernel's registered fileset.
///
/// Valid `Registe
    
    unsafe fn prep_write(self, fd: impl UringFd, sqe: &mut SQE<'_>, offset: u64) {
        uring_sys::io_uring_prep_write_fixed(
            sqe.raw_mut(),
            fd.as_raw_fd(),
            self.data.as_ptr() as _,
            self.data.len() as _,
            offset as _,
            self.index() as _,
        );
        fd.update_sqe(sqe);
    }