ChickenDB<String, User> db = new ChickenDB<>();

/**
 * This Filter helps to find all User with the given Status
 */
public class StatusFilter  implements IFilter<User> {
  private Status status;
	
  /**
   * @param status The given status
   */
  public StatusFilter(Status status) {
    this.status = status;
  }
	
  /**
    * Validator method
    */
  @Override
  public boolean validate(User item) {
    return item.getStatus() == status;
  }
}

ChickenDB<String, User> result = db.filter(new StatusFilter(Status.ONLINE))
                                   .filter(/* Other filter... */);

ChickenDB<String, User> result = db.filter(user -> user.getStatus() == Status.ONLINE)
                                   .filter(/* Other filter... */);