code: public Collection<SideBarItemDescriptor> getSideBarItems(SideBarSectionDescriptor descriptor) {
          List<SideBarItemDescriptor> supportedItems = new ArrayList<SideBarItemDescriptor>();
          for (SideBarItemDescriptor item : items) {
              if (item.isMemberOfSection(descriptor)) {
                  supportedItems.add(item);
              }
          }
          return supportedItems;
      }
docs: Gets all side bar items for the specified side bar section.
  
  @param descriptor descriptor the side bar section descriptor, must not be {@code null}.
  @return a collection of side bar item descriptors, never {@code null}.