如何在Rails中创建具有many_to_many关系的独立模型的嵌套形式？

rails generate model ModelA name:string
rails generate model ModelB name:string
rails db:migrate

rails generate model ModelC model_a:references model_b:references
rails db:migrate

class ModelA < ApplicationRecord
  has_many :model_cs
  has_many :model_bs, through: :model_cs
end

class ModelB < ApplicationRecord
  has_many :model_cs
  has_many :model_as, through: :model_cs
end

class ModelC < ApplicationRecord
  belongs_to :model_a
  belongs_to :model_b
end

model_a = ModelA.create(name: "ModelA 1")
model_b1 = ModelB.create(name: "ModelB 1")
model_b2 = ModelB.create(name: "ModelB 2")

model_a.model_bs << model_b1
model_a.model_bs << model_b2