private MethodInfo createMethodForDoRunCleanupSpec(SpockExecutionContext context, final SpecInfo spec) {
    MethodInfo result = new MethodInfo((Object target, Object... arguments) -> {
        doRunCleanupSpec(context, spec);
        return null;
      }
    );
    result.setParent(spec);
    result.setKind(MethodKind.CLEANUP_SPEC);
    spec.getCleanupSpecInterceptors().forEach(result::addInterceptor);
    return result;
  }
Executes a single Spec. Notifies its supervisor about overall execution
progress and every invocation of Spec code.
Supervisor also determines the error strategy.

@author Peter Niederwieser
spock-core/src/main/java/org/spockframework/runtime/PlatformSpecRunner.java