def constraint(self, PreNode, graph):
    '\n                Executable constraint code.\n                @param PreNode: Function taking an integer as parameter\n                                        and returns the node corresponding to that label.\n                '
    return True
Executable constraint code.
@param PreNode: Function taking an integer as parameter
                        and returns the node corresponding to that label.
def constraint(self, PreNode, graph):
    '\n                Executable constraint code.\n                @param PreNode: Function taking an integer as parameter\n                                        and returns the node corresponding to that label.\n                '
    return True