SpaceXService.kt

@GET("rockets")
fun getRocketsAsync(): Deferred<Response<List<Rocket>>>

@GET("launches/upcoming")
fun getNextFlightsAsync(): Deferred<Response<List<Flight>>>

@GET("history")
fun getPastEventsAsync(): Deferred<Response<List<Event>>>

companion object {
    fun create(): SpaceXService {
        return Retrofit.Builder()
            .baseUrl(BuildConfig.SPACEX_API_URL)
            .addConverterFactory(GsonConverterFactory.create())
            .addCallAdapterFactory(CoroutineCallAdapterFactory())
            .build()
            .create(SpaceXService::class.java)
    }
}