Network calls with kotlin coroutine + Android Architecture components

ApiClient.kt

object ApiClient {

        fun getIntance(): ApiStores {

            val builder = OkHttpClient.Builder()
           
            if (BuildConfig.DEBUG) {
                val loggingInterceptor = HttpLoggingInterceptor()
                loggingInterceptor.level = HttpLoggingInterceptor.Level.BODY
                builder.addInterceptor(loggingInterceptor)

            }

            val okHttpClient = builder.build()

            val retrofit = Retrofit.Builder()
                    .baseUrl(ApiStores.API_SERVER_URL)
                    .addConverterFactory(ScalarsConverterFactory.create())
                    .addConverterFactory(retrofit2.converter.gson.GsonConverterFactory.create())
                    .addCallAdapterFactory(CoroutineCallAdapterFactory())
                    .client(okHttpClient)
                    .build()
            return retrofit.create(ApiStores::class.java)
    }
}

ApiStores.kt

interface ApiStores { 
   companion object {
       const val API_SERVER_URL = "somebaseurl"
    }
  
  
  @GET("group/listSchools")
    fun listSchool(@Header("Authorization") token: String): Deferred<Wrapper<List<School?>?>>
  
  
}