How to use StorageString?

I was trying to use StorageString to save string values according to this file.

But when I run it in the playground, it gives me the below error.

No method named "write_slice" found for type "StorageKey<StorageString>".

Here is the code I ran,

contract;

use std::{storage::storage_string::StorageString, bytes::Bytes, string::String};

storage {
 stored_string: StorageString = StorageString {}
}

 fn foo() {
    let mut bytes = Bytes::new();
    bytes.push(5_u8);
    bytes.push(7_u8);
    bytes.push(9_u8);
    let string = String::from(bytes);

    storage.stored_string.write_slice(string);
 }

This is a current bug/limitation of the compiler, you need to glob import (std::storage::storage_string::*) in order to import the methods for a implementation on a type of that form