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: error.rs
    path of file: ./repos/gluon/base/src
    
    the code of the file until where you have to start completion: //! Module containing a few common error wrappers which allows more information to be saved for
//! later display to the user

use std::any::Any;
use std::error::Error as StdError;
use std::fmt;
use std::iter::{Extend, FromIterator};
use std::ops::{Index, 
    
    fn as_diagnostic(&self, map: &crate::source::CodeMap) -> Diagnostic<FileId> {
        let mut diagnostic = self.error.as_diagnostic(map);
        if let Some(ref help) = self.help {
            diagnostic.labels.push(
                Label::secondary(
                    diagnostic
                        .labels
                        .last()
                        .map(|label| label.file_id)
                        .unwrap_or_default(),
                    0..0,
                )
                .with_message(help.to_string()),
            );
        }
        diagnostic
    }