Function string_key_to_btree_map

pub fn string_key_to_btree_map<'de, K, V, D>(
    deserializer: D,
) -> Result<BTreeMap<K, V>, D::Error>
where
    K: FromStr + Ord + Debug,
    K::Err: Display,
    V: Deserialize<'de>,
    D: Deserializer<'de>,

Used to deserialize fields of std::collections::BTreeMap whose key type is not a native string. Annotate the field with #[serde(deserialize_with = "mz_ore::serde::string_key_to_btree_map")].