Namespacing with enums 2

namespacing2.swift

enum API {
    enum AirVisual {
        static let BaseURL = "api.airvisual.com/v2/nearest_city?lat={{LATITUDE}}&lon={{LONGITUDE}}&key={{YOUR_API_KEY}}"
        static let Key = "you_api_key"
    }
    enum PropellerAir {
        static let BaseURL = "https://open.propellerhealth.com/prod/forecast?latitude={{LATITUDE}}&longitude={{LONGITUDE}}"
    }
}

let url1 = API.AirVisual.BaseURL
let key = API.AirVisual.Key
let url2 = API.PropellerAir.BaseURL