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: screen.rs
    path of file: ./repos/tock/capsules/extra/src
    
    the code of the file until where you have to start completion: // Licensed under the Apache License, Version 2.0 or the MIT License.
// SPDX-License-Identifier: Apache-2.0 OR MIT
// Copyright Tock Contributors 2022.

//! Provides userspace with access to the screen.
//!
//! Usage
//! -----
//!
//! You need a screen that provides the `hil::screen::Screen` trait.
//!
//! ```rust
//! let screen =
//!     components::screen::ScreenCom
    
    fn write_complete(&self, data: SubSliceMut<'static, u8>, r: Result<(), ErrorCode>) {
        let buffer = data.take();
        let len = self.fill_next_buffer_for_write(buffer);

        if r == Ok(()) && len > 0 {
            let mut data = SubSliceMut::new(buffer);
            data.slice(..len);
            let _ = self.screen.write(data, true);
        } else {
            self.buffer.replace(buffer);
            self.run_next_command(kernel::errorcode::into_statuscode(r), 0, 0);
        }
    }