def node_changed(self, node):
        """
        Calls :meth:`QAbstractItemModel.dataChanged` with given Node index.

        :param node: Node.
        :type node: AbstractCompositeNode or GraphModelNode
        :return: Method success.
        :rtype: bool
        """

        index = self.get_node_index(node)
        if index is not None:
            self.dataChanged.emit(index, index)
            return True
        else:
            return False
Calls :meth:`QAbstractItemModel.dataChanged` with given Node index.

        :param node: Node.
        :type node: AbstractCompositeNode or GraphModelNode
        :return: Method success.
        :rtype: bool