public static CoroutineAsyncBridge <AsyncOperation> GetAwaiter(this AsyncOperation asyncOperation)
 {
     return(CoroutineAsyncBridge <AsyncOperation> .Start(asyncOperation));
 }
 public static CoroutineAsyncBridge GetAwaiter(this IEnumerator coroutine)
 {
     return(CoroutineAsyncBridge.Start(coroutine));
 }
 public static CoroutineAsyncBridge <WWW> GetAwaiter(this WWW www)
 {
     return(CoroutineAsyncBridge <WWW> .Start(www));
 }