default void visitFixtureAnnotation(T annotation, MethodInfo fixtureMethod) {
    throw new InvalidSpecException("@%s may not be applied to fixture methods")
      .withArgs(annotation.annotationType().getSimpleName());
  }
Handles the annotation when applied to a fixture method of a specification.
The default implementation of this method throws an {@link InvalidSpecException}.
This method is not called by Spock directly, but only by the default implementation of
{@link #visitFixtureAnnotations(List, MethodInfo)}, so if you have overwritten that method,
there is no need to overwrite this one too except if you want to call it yourself.

@param annotation    the annotation found on the fixture method
@param fixtureMethod the annotated fixture method
spock-core/src/main/java/org/spockframework/runtime/extension/IAnnotationDrivenExtension.java