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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 _construct_connector(self, pos):
 """ build widget to be used as "connector" bit between the vertical bar between siblings and their respective horizontal bars leading to the arrow tip """

        # connector symbol, either L or |- shaped.
        connectorw = None
        connector = None
        if self._tree.next_sibling_position(pos) is not None:  # |- shaped
            if self._arrow_connector_tchar is not None:
                connectorw = urwid.Text(self._arrow_connector_tchar)
        else:  # L shaped
            if self._arrow_connector_lchar is not None:
                connectorw = urwid.Text(self._arrow_connector_lchar)
        if connectorw is not None:
            att = self._arrow_connector_att or self._arrow_att
            connector = urwid.AttrMap(connectorw, att)
        return connector