Editing NUnit (section)

=== Constraint based ===
Beginning with NUnit 2.4, a new ''Constraint-based'' model was introduced. This approach uses a single method of the <code>Assert</code> class for all assertions, passing a <code>Constraint</code> object that specifies the test to be performed. This constraint-based model is now used internally by NUnit for all assertions. The methods of the classic approach have been re-implemented on top of this new model.{{citation needed|date=January 2017}}