return null;
                    }
                    try {
                        ModelBuildingRequest gaBuildingRequest =
                                new DefaultModelBuildingRequest(request).setModelSource(source);
                        return defaultModelBuilder.readRawModel(gaBuildingRequest, problems);
                    } catch (ModelBuildingException e) {
                        // gathered with problem collector

    }

    @Override
    public ModelSource getModelSource() {
        return request.getModelSource();
    }

    @Override
    public FilterModelBuildingRequest setModelSource(ModelSource modelSource) {
        request.setModelSource(modelSource);

        return this;
    }

    @Override
    public int getValidationLevel() {
        return request.getValidationLevel();
    }

    @Override