private void doRunCleanup(SpockExecutionContext context, SpecInfo spec) {
    if (spec.getIsBottomSpec()) {
      runIterationCleanups(context);
    }
    for (MethodInfo method : spec.getCleanupMethods()) {
      invoke(context, context.getCurrentInstance(), method);
    }
    runCleanup(context, spec.getSuperSpec());
  }
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