code: public Collection<Task> getTasks(TaskFilter filter) {
          filter = (filter != null) ? filter : new TaskFilter();
  
          return getInstance().get().tasks(getFilter(filter, false));
      }
docs: Get Tasks in this Project filtered as specified in the passed in filter.
  
  @param filter Criteria to filter on. Project will be set automatically.
  If null, all tasks in the project are returned.
  @return An Collection of SecondaryWorkitem.