public void CreateBatch()
{
object asyncState = new object();
IBatch innerBatch = new Mock <IBatch>().Object;
mock.Setup(_ => _.CreateBatch(asyncState)).Returns(innerBatch);
IBatch wrappedBatch = wrapper.CreateBatch(asyncState);
mock.Verify(_ => _.CreateBatch(asyncState));
Assert.IsInstanceOf <BatchWrapper>(wrappedBatch);
Assert.AreSame(innerBatch, ((BatchWrapper)wrappedBatch).Inner);
}