code: def add_reftrack(self, reftrack):
          
          self._reftracks.add(reftrack)
          refobj = reftrack.get_refobj()
          if refobj:
              self._parentsearchdict[refobj] = reftrack
docs: Add a reftrack object to the root.
  
          This will not handle row insertion in the model!
          It is automatically done when setting the parent of the :class:`Reftrack` object.
  
          :param reftrack: the reftrack object to add
          :type reftrack: :class:`Reftrack`
          :returns: None
          :rtype: None
          :raises: None