suspendReturnInsideListener.kt

private suspend fun getToken(foo: String): String? = suspendCoroutine { continuation ->
      val fooToken = tokenApiExample.Token(foo).start
        fooToken.onCreateTokenListener { data ->
                when {
                    data.has("id") -> {
                        val token = data.getString("id")
                        continuation.resume(token)
                    }
                    else -> {
                        continuation.resume(null)
                    }
                }
            }                                                        
    }