wro4j-core/src/main/java/ro/isdc/wro/model/resource/support/change/ResourceChangeInfo.java
public void updateHashForGroup(final String hash, final String groupName) {
    notNull(groupName);
    this.currentHash = hash;
    if (isChangedHash()) {
      LOG.debug("Group {} has changed", groupName);
      //remove all persisted groups. Starting over..
      groups.clear();
    }
  }
public void updateHashForGroup(final String hash, final String groupName) {
    notNull(groupName);
    this.currentHash = hash;
    if (isChangedHash()) {
      LOG.debug("Group {} has changed", groupName);
      //remove all persisted groups. Starting over..
      groups.clear();
    }
  }
Updates the hash associated with the resource for a give groupName.

@param hash
the most recent computed hash.
@param groupName
name of the group for which the change of resource is detected.