Your mock example could be improved (in both languages) by defining a variable for the Y mock. You probably want a variable anyway, so you can define the mock’s

Your mock example could be improved (in both languages) by defining a variable for the Y mock. You probably want a variable anyway, so you can define the mock’s behaviour or verify it was used correctly. Also, Java’s a pretty bad example, as it lacks default arguments and named arguments, leading to the ugly and verbose builder pattern. (Side note, why didn’t Java add them yet, after so many years of their usefulness being seen in Scala, Kotlin, C# to name a few related languages?)