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: mod.rs
    path of file: ./repos/poem/poem/src/web
    
    the code of the file until where you have to start completion: //! Commonly used as the type of extractor or response.

mod accept;
mod addr;
#[cfg(feature = "compression")]
mod compress;
#[cfg(feature = "coo
    
///     async fn from_request(req: &'a Request, body: &mut RequestBody) -> Result<Self> {
///         let token = req
///             .headers()
///             .get("MyToken")
///             .and_then(|value| value.to_str().ok())
///             .ok_or_else(|| Error::from_string("missing token", StatusCode::BAD_REQUEST))?;
///         Ok(Token(token.to_string()))
///     }