wro4j-core/src/main/java/ro/isdc/wro/model/group/Group.java
public final void setResources(final List<Resource> resources) {
    notNull(resources);
    synchronized (this) {
      this.resources.clear();
      for (final Resource resource : resources) {
        addResource(resource);
      }
    }
  }
public final void setResources(final List<Resource> resources) {
    notNull(resources);
    synchronized (this) {
      this.resources.clear();
      for (final Resource resource : resources) {
        addResource(resource);
      }
    }
  }
This method will replace all earlier defined resources with the provided list of resources.
<p/>
The implementation is synchronized, because it mutates the collection.

@param resources
the resources to replace the underlying resources.