@Beta
  public void addInitializerInterceptor(IMethodInterceptor interceptor) {
    initializerInterceptors.add(interceptor);
  }
Adds an initializer interceptor for this feature.
<p>
The feature-scoped interceptors will execute before the spec interceptors.

@since 2.4
spock-core/src/main/java/org/spockframework/runtime/model/FeatureInfo.java