Indicates the source to be used to provide test fixture instances for a test class. The name parameter is a String representing the name of the source used to provide test cases. It has the following characteristics:It must be a static field, property, or method in the same class as the test case.It must return an IEnumerable or a type that implements IEnumerable, such as an array, a List, or your own iterator.Each item returned by the enumerator must be compatible with the signature of the method on which the attribute appears.