如何在docplex中删除一批约束？

from docplex.mp.model import Model

# 创建一个模型
model = Model(name='example_model')

# 添加一些约束
constraint1 = model.add_constraint(x + y <= 10, ctname='constraint1')
constraint2 = model.add_constraint(x - y >= 5, ctname='constraint2')
constraint3 = model.add_constraint(2*x + 3*y == 20, ctname='constraint3')

# 删除约束
constraints_to_remove = [constraint1, constraint2, constraint3]
for constraint in constraints_to_remove:
    model.remove_constraint(constraint)

# 打印剩余的约束
print(model.export_to_string())