extension Weather publisher. For article: https://medium.com/p/4ddf8710d1a0/

Weather+publisher.swift

import Combine

extension Weather {
    static func publisher(
        city: String,
        countryCode: String?,
        system: System
    ) {
        publisher(
            keyValues: [
                .appID: "1234567890abcdef",
                .site: [city, countryCode]
                    .compactMap { $0 }
                    .joined(separator: ","),
                .system: system
            ]
        )
    }
}