code: public IScope getFeatureScope(/* @Nullable */ XAbstractFeatureCall currentFeatureCall, Anchor anchor) {
  		if (anchor == Anchor.RECEIVER) {
  			if (currentFeatureCall == requestedFeatureCall && cachedReceiverFeatureScope != null) {
  				return cachedReceiverFeatureScope;
  			}
  			IScope result =  createFeatureCallScopeForReceiver(currentFeatureCall);
  			this.requestedFeatureCall = currentFeatureCall;
  			return cachedReceiverFeatureScope = result;
  		}
  		return getFeatureScope(anchor);
  	}
docs: /* @NonNull