public Object getTestInstance() {
    if (getTestInstanceMethod == null) {
      throw new SpringExtensionException("Method 'TestContext.getTestInstance()' was not found");
    }
    return ReflectionUtil.invokeMethod(delegate, getTestInstanceMethod);
  }
Wrapper around Spring's TestContext class that works with Spring 2.5 and Spring 3.
spock-spring/src/main/java/org/spockframework/spring/SpringTestContext.java