ApiService.kt

interface ApiService {

    @GET("photos")
    suspend fun getPhotos(@Query("sol") sol: Int, @Query("api_key") apiKey: String, @Query("page") page: Int): Response<PhotosResponse>?
}

object RetrofitService {

    var client: OkHttpClient = OkHttpClient.Builder().build()

    private var retrofit = Retrofit.Builder().baseUrl(BuildConfig.BASE_URL)
        .addConverterFactory(GsonConverterFactory.create()).client(client).build()

    fun <T> createService(serviceClass: Class<T>): T = retrofit.create(serviceClass)
}