ClassInitialize
ClassInitialize is a method in the MSTest framework used to perform class-level setup before any tests in a test class are executed. It enables initialization of resources that are shared among all tests in the class, such as database connections, external services, or large test data sets. The method is called once per test class and helps avoid repeating expensive setup code for each test method.
For a method to serve as ClassInitialize, it must be public and static, return void, and accept
ClassInitialize runs before any TestMethod in the class and only once per class, which distinguishes it from
A ClassCleanup method, annotated with ClassCleanup, often accompanies ClassInitialize to release the resources after all tests