public async Task BuildThrowsWhenBothPartitionProcessorFactoriesSpecified()
{
builder
.WithFeedDocumentClient(CreateMockDocumentClient())
.WithLeaseDocumentClient(CreateMockDocumentClient())
.WithObserverFactory(Mock.Of <IChangeFeedObserverFactory>())
.WithPartitionProcessorFactory(Mock.Of <IPartitionProcessorFactory>())
.WithCheckpointPartitionProcessorFactory(Mock.Of <ICheckpointPartitionProcessorFactory>());
await Assert.ThrowsAsync <ArgumentException>(async() => await builder.BuildAsync());
}