MyDataSource.kt

<!-- Copyright 2020 Google LLC.	
   SPDX-License-Identifier: Apache-2.0 -->

suspend fun doOneShot(param: String) : Result<String> =
    suspendCancellableCoroutine { continuation ->
        api.addOnCompleteListener { result ->
            continuation.resume(result)
        }.addOnFailureListener { error ->
            continuation.resumeWithException(error)
        }.fetchSomething(param)
      }