public async Task TestInsertTelemetryAndUpdateRobotsAsync_UpsertTelemetry_ExpectedExecutions(int numItems)
{
mockCosmosClientTelemetry.Setup(x =>
x.UpsertItemAsync(It.IsAny <RobotTelemetry>(), It.IsAny <PartitionKey>())).Throws(new Exception("invalid"));
FleetManager fleetManager = new FleetManager(mockIotClient.Object, mockCosmosClientRobot.Object, telemetryHandler, mockLogger.Object);
IEnumerable <RobotTelemetry> testTelemetry = GetTestTelemetry(numItems);
// should not throw exception
await fleetManager.InsertTelemetriesAndUpdateRobotsAsync(testTelemetry);
mockCosmosClientTelemetry.Verify(x => x.UpsertItemAsync(It.IsAny <RobotTelemetry>(), It.IsAny <PartitionKey>()), Times.Exactly(numItems));
}