question: how to resolve impl Borrow<UniCase<'a>> for UniCase<&'static str>

[OliverNChalk]

I have a minimal RustExplorer example that shows me struggling with a problem documented here in phf_shared's docs.

Key Snippet:

fn test(key: &str) {
    let map: HashMap<MyStruct, u32> = HashMap::new();
    let phf_map: phf::Map<MyStruct, u32> = phf::Map::new();

    let key = MyStruct { key };
    map.get(&key);
    phf_map.get(&key); // <- fails to compile
}

The docs mention:

Instead, this trait is implemented conservatively, without blanket impls, so that impls like this may be added. This is feasible since the set of types that implement PhfHash is intentionally small.

How might I go about solving this issue in concrete code terms?