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: context.rs
    path of file: ./repos/hash/libs/error-stack/src
    
    the code of the file until where you have to start completion: #[cfg(nightly)]
use core::error::{Error, Request};
use core::fmt;
#[cfg(all(not(nightly), feature = "std"))]
use std::error::Error;

use crate::Report;

/// Defines the current context of a [`Report`].
///
/// When in a `std` environment or on a nightly toolchain, every [`Erro
    
/// pub fn parse_config(path: &str) -> Result<Config, ConfigError> {
///     // The return type of `parse_config` requires another context. By calling `change_context`
///     // the context may be changed.
///     read_file(path).change_context(ConfigError::ParseError)?;
///
///     # const _: &str = stringify! {
///     ...
///     # }; Ok(())
/// }