title: Unresolved reference: await. Kotlin coroutines
body: <p>I'm trying to get data from Api using Retrofit 2 and coroutines. From my GetRepositoriesUseCase I start coroutine but 'await()' function is an unresolved reference.</p>
  
  <p>ViewModel:</p>
  
  <pre><code>fun getRepositoryList()  {
      getRepositoriesUseCase(textLiveData.value.toString(), viewModelScope) { result -&gt;
          result.onSuccess { repositoriesList.value = it }
          result.onFailure { show(it.message.toString()) }
      }
  }
  </code></pre>
  
  <p>GetRepositoriesUseCase:</p>
  
  <pre><code>class GetRepositoriesUseCase(private val repository: ApiRepository) {
  
  operator fun invoke(
      key: String,
      coroutineScope: CoroutineScope,
      onResult: (Result&lt;Collection&lt;Repository&gt;&gt;) -&gt; Unit
  ) {
      coroutineScope.launch {
          val result = withContext(Dispatchers.IO) {
              runCatching { repository.getRepositories(key) }
          }
          onResult(result)
      }
  }}
  </code></pre>
  
  <p>ApiRepository (here I get error):</p>
  
  <pre><code>class ApiRepository(private val api: GitHubApi) {
  
  fun getRepositories(key: String): Collection&lt;Repository&gt; {
      return api.getRepository(key).await().list
  }}
  </code></pre>
  
  <p>Api:</p>
  
  <pre><code>interface GitHubApi{
  
  @GET("search/repositories")
  fun getRepository(@Query("q") query: String)
  }
  </code></pre>