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: body.rs
    path of file: ./repos/fluke/crates/fluke/src/h2
    
    the code of the file until where you have to start completion: use tokio::sync::mpsc;

use crate::{Body, BodyChunk, Headers};
use fluke_buffet::Piece;

pub(crate) enum PieceOrTrailers {
    Piece(Piece),
    Trailers(Box<Headers>),
}

pub(crate) type H2BodySender = mpsc::Sender<H2BodyItem>;
pub(crate) type H2BodyItem = eyre::Result<PieceOrTrailers>;

#[derive(Debug)]
pub(crate) struct H2Body {
    pub(crate) content_length: Option<u64>,
    pub(crate) eof: bool,
    // TODO: more specific error handling
    pub(crate) rx: mpsc::Receiver<H2BodyItem>,
}

impl Body for H2Body {
    fn content_len(&self) -> Option<u64> {
        self.content_length
    }

    fn eof(&self) -> bool {
        self.eof
    }

    async fn next_chunk(&mut self) -> eyre::Re
    
    async fn next_chunk(&mut self) -> eyre::Result<BodyChunk> {
        let chunk = if self.eof {
            BodyChunk::Done { trailers: None }
        } else {
            match self.rx.recv().await {
                Some(maybe_piece_or_trailers) => match maybe_piece_or_trailers? {
                    PieceOrTrailers::Piece(piece) => BodyChunk::Chunk(piece),
                    PieceOrTrailers::Trailers(trailers) => {
                        self.eof = true;
                        BodyChunk::Done {
                            trailers: Some(trailers),
                        }
                    }
                },
                // TODO: handle trailers
                None => {
                    self.eof = true;
                    BodyChunk::Done { trailers: None }
                }
            }
        };
        Ok(chunk)
    }