182 		rowref = self._root
184 			rowref = rowref[path[0]]
186 		return rowref
188 	def on_get_path(self, rowref):  argument
190 		while rowref != self._root:
191 			path.append(rowref.get_index())
192 			rowref = rowref.get_parent()
196 	def on_get_value(self, rowref, column):  argument
198 			return rowref.get_key()
200 			return rowref.get_value_str()
202 	def on_iter_next(self, rowref):  argument
203 		return rowref.get_parent()[rowref.get_index() + 1]
205 	def on_iter_children(self, rowref):  argument
206 		return rowref[0]
208 	def on_iter_has_child(self, rowref):  argument
209 		return bool(len(rowref))
211 	def on_iter_n_children(self, rowref):  argument
212 		return len(rowref)
214 	def on_iter_nth_child(self, rowref, n):  argument
215 		if not rowref: rowref = self._root
216 		return rowref[n]
218 	def on_iter_parent(self, rowref):  argument
219 		return rowref.get_parent()