[Callback to Coroutines] use suspendCoroutine. #Kotlin

sample.kt

/*
  before
  
  fun asyncLoad(callback: (result: String) -> Unit) {
    load { result ->
      callback(result)
    }
  }
*/
suspend fun asyncLoad(): String = suspendCoroutine { continuation ->
    load { result ->
        if (result.isEmpty()) {
          continuation.resumeWithException(LoadError())
        } else {
          continuation.resume(result)
        }
    }
}