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: index_uid.rs
    path of file: ./repos/meilisearch/meilisearch-types/src
    
    the code of the file until where you have to start completion: use std::error::Error;
use std::fmt;
use std::str::FromStr;

use deserr::Deserr;

use crate::error::{Code, ErrorCode};

/// An index uid is composed of only ascii alphanumeric characters, - and _, between 1 and 400
/// byte
    
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        write!(
            f,
            "`{}` is not a valid index uid. Index uid can be an \
            integer or a string containing only alphanumeric \
            characters, hyphens (-) and underscores (_).",
            self.invalid_uid,
        )
    }