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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def remove_reftrack(self, reftrack):
 """Remove the reftrack from the root. This will not handle row deletion in the model! It is automatically done when calling :meth:`Reftrack.delete`. :param reftrack: the reftrack object to remove :type reftrack: :class:`Reftrack` :returns: None :rtype: None :raises: None """

        self._reftracks.remove(reftrack)
        refobj = reftrack.get_refobj()
        if refobj and refobj in self._parentsearchdict:
            del self._parentsearchdict[refobj]