/wro4j-core/src/main/java/ro/isdc/wro/manager/WroManager.java
notNull( cacheKeyFactory) ;notNull( groupExtractor) ;
notNull ( groupExtractor ) ;
} public Builder setModelFactory(final WroModelFactory modelFactory) { this.modelFactory = modelFactory; return this; } public Builder setGroupExtractor(final GroupExtractor groupExtractor) { <extra_id_0> this.groupExtractor = groupExtractor; return this; } public Builder setCacheStrategy(final CacheStrategy<CacheKey, CacheValue> cacheStrategy) { notNull(cacheStrategy); this.cacheStrategy = cacheStrategy;