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: extractor.rs
    path of file: ./repos/actix-web/actix-multipart/src
    
    the code of the file until where you have to start completion: //! Multipart payload support

use actix_utils::future::{ready, Ready};
use actix_web::{dev::Payload, Error, FromRequest, HttpRequest};

use crate::server::Multipart;

/// Get request's payload as multipart stream
    
/// async fn index(mut payload: Multipart) -> Result<HttpResponse, Error> {
///     // iterate over multipart stream
///     while let Some(item) = payload.next().await {
///            let mut field = item?;
///
///            // Field in turn is stream of *Bytes* object
///            while let Some(chunk) = field.next().await {
///                println!("-- CHUNK: \n{:?}", std::str::from_utf8(&chunk?));
///            }
///     }
///
///     Ok(HttpResponse::Ok().into())
/// }