Is there anything wrong with a class with all static methods?

Question

I\'m doing code review and came across a class that uses all static methods. The entrance method takes several arguments and then starts calling the other static methods passin

Answer 1

One of the disadvantages of using a static class is that its clients cannot replace it by a test double in order to be unit tested.

In the same way, it's harder to unit test a static class because its collaborators cannot be replaced by test doubles (actually,this happens with all the classes that are not dependency-injected).