code: public Collection<Epic> getEpics(EpicFilter filter) {
          filter = (filter != null) ? filter : new EpicFilter();
  
          filter.goals.clear();
          filter.goals.add(this);
          return getInstance().get().epics(filter);
      }
docs: Epics assigned to this Goal.
  
  @param filter Limit the epic returned (If null, then all items returned).
  @return A collection epics that belong to this goal filtered by the
  passed in filter.