Represents a contract for annotations, which serves as arguments provider for parametrized tests. These annotations are used on parameters and are resolved during execution of parameterized tests. Basic implementation is annotation parameters(), but custom implementation can be very easily implemented, see example below.

Example (random annotation is custom implementation of ArgumentProvider, which returns random number for every test):

shared annotation RandomAnnotation random() => RandomAnnotation();

shared final annotation class RandomAnnotation()
         satisfies OptionalAnnotation<RandomAnnotation,FunctionOrValueDeclaration> & ArgumentProvider {

    shared actual {Anything*} arguments(ArgumentProviderContext context)
         => randomGenerator.nextInteger();

}

test
shared void shouldGuessNumber(random Integer num) {
    assert(magician.guessNumber() == num);
}