The following is written on the project's home page:
Proper unit tests should fail for exactly one reason, that’s why you should be using one assert per unit test.
And, also, Roy wrote in comments:
My guideline is usually that you test one logical CONCEPT per test. you can have multiple asserts on the same object. they will usually be the same concept being tested.
I think that, there are some cases where multiple assertions are needed (e.g. Guard Assertion), but in general I try to avoid this. What is your opinion? Please provide a real world example where multiple asserts are really needed.