如何在Google OR-Tools中设置每条路线的最小位置？

from ortools.constraint_solver import routing_enums_pb2
from ortools.constraint_solver import pywrapcp

def create_data_model():
    data = {}
    # 定义节点位置
    data['locations'] = [
        (4, 4),  # 起始位置
        (2, 0),  # 节点 1
        (8, 0),  # 节点 2
        (0, 1),  # 节点 3
        (1, 2),  # 节点 4
        (5, 2),  # 节点 5
        (7, 2),  # 节点 6
        (3, 3),  # 节点 7
        (6, 3),  # 节点 8
        (5, 5),  # 节点 9
        (8, 5),  # 节点 10
        (1, 6),  # 节点 11
        (2, 7),  # 节点 12
        (3, 7),  # 节点 13
        (6, 7),  # 节点 14
        (0, 8),  # 节点 15
        (7, 8)  # 节点 16
    ]
    data['num_locations'] = len(data['locations'])
    data['num_vehicles'] = 1
    data['depot'] = 0
    return data

def main():
    data = create_data_model()

    # 创建一个Solver对象
    manager = pywrapcp.RoutingIndexManager(data['num_locations'], data['num_vehicles'], data['depot'])
    routing = pywrapcp.RoutingModel(manager)

    # 设置节点位置
    for i, location in enumerate(data['locations']):
        routing.AddDisjunction([manager.NodeToIndex(i)], 1000)  # 设置惩罚成本

    # 设置位置约束
    dimension_name = 'Location'
    routing.AddDimension(
        routing.RegisterTransitCallback(lambda from_index, to_index: manager.Distance(from_index, to_index)),
        0, 100, True, dimension_name)

    # 设置每条路线的最小位置
    nodes = [1, 2, 3]  # 设置节点 1, 2, 3 的最小位置
    penalty = 1000
    routing.AddSoftSameVehicleConstraint(nodes, penalty)

    # 设置搜索参数
    search_parameters = pywrapcp.DefaultRoutingSearchParameters()
    search_parameters.first_solution_strategy = (
        routing_enums_pb2.FirstSolutionStrategy.PATH_CHEAPEST_ARC)

    # 解决问题
    solution = routing.SolveWithParameters(search_parameters)

    # 输出结果
    if solution:
        print_solution(manager, routing, solution)

def print_solution(manager, routing, solution):
    print('Objective: {}'.format(solution.ObjectiveValue()))
    index = routing.Start(0)
    plan_output = 'Route:\n'
    route_distance = 0
    while not routing.IsEnd(index):
        plan_output += ' {} ->'.format(manager.IndexToNode(index))
        previous_index = index
        index = solution.Value(routing.NextVar(index))
        route_distance += routing.GetArcCostForVehicle(previous_index, index, 0)
    plan_output += ' {}\n'.format(manager.IndexToNode(index))
    route_distance += routing.GetArcCostForVehicle(previous_index, index, 0)
    plan_output += 'Distance of the route: {}\n'.format(route_distance)
    print(plan_output)

if __name__ == '__main__':
    main()