There is a question-discussion about having unit tests without assertions. But there is also another question which might need some discussion:
Is it a good practice to have non-test method(s) having assertions in xUnit or Integration test class, which is(are) used in test methods inside the same or other test classes?
EDIT: How to implement a case, when you have several test cases which are required to run in a specific order and running in that order those multiple test cases construct another test case? Is it good to implement those test cases as non-test methods with assertions and then have one test method which calls all these chained methods in an order?