Annotation Type TestContext
Marks the field in test class defining a
ExternalContextFactory for constructing ExternalContext before invocation of each test case.
Multiple fields can be annotated as external context factory, and these external contexts will be provided as different parameters of test cases.
The lifecycle of a ExternalContext will be PER-CASE, which means an instance of ExternalContext will be constructed before invocation of each test case, and closed right after
the execution of the case for isolation between test cases.