You have to cover the execution of every method of the class with UT and check the method return value. This includes getters and setters, especially in case the members(properties) are complex classes, which requires large memory allocation during their initialization. Call the setter with some very large string for example (or something with greek symbols) and check the result is correct (not truncated, encoding is good e.t.c.)
In case of simple integers that also applies - what happens if you pass long instead of integer? That's the reason you write UT for :)
