Code Inspection: NUnit. Expected non-abstract class implementing IEnumerable
NUnit's TestCaseSource attribute is used to identify the source from which the argument(s) will be provided for a parameterized test. The class that provides test cases must have a default constructor and implement
IEnumerable. If the test source class does not implement
IEnumerable, ReSharper issues a warning.
Note that NUnit allows different ways of specifying test case sources. For details, refer to the TestCaseSourceAttribute documentation.