docs: def fragments(self, req, tag):
          """
          Render our preference collection, any child preference
          collections we discover by looking at self.tab.children,
          and any fragments returned by its C{getSections} method.
  
          Subtabs and C{getSections} fragments are rendered as fieldsets
          inside the parent preference collection's tab.
          """
          f = self._collectionToLiveform()
          if f is not None:
              yield tags.fieldset[tags.legend[self.tab.name], f]
  
          for t in self.tab.children:
              f = inevow.IRenderer(
                      self.collection.store.getItemByID(t.storeID))
              f.tab = t
              if hasattr(f, 'setFragmentParent'):
                  f.setFragmentParent(self)
              yield f
  
          for f in self.collection.getSections() or ():
              f = ixmantissa.INavigableFragment(f)
              f.setFragmentParent(self)
              f.docFactory = getLoader(f.fragmentName)
              yield tags.fieldset[tags.legend[f.title], f]