code: public Collection<Project> getTargetedBy(ProjectFilter filter) {
          filter = (filter != null) ? filter : new ProjectFilter();
  
          filter.targets.clear();
          filter.targets.add(this);
          return getInstance().get().projects(filter);
      }
docs: A collection of Projects Targeted by this Goal.
  
  @param filter Limit the project returned (If null, then all items
  returned).
  @return A collection projects that belong to this goal filtered by the
  passed in filter.