如何将nested_form gem与新的与现有嵌套模型对象的不同部分一起使用？

gem 'nested_form'

class Survey< ApplicationRecord
  has_many :questions, dependent: :destroy
  accepts_nested_attributes_for :questions, allow_destroy: true
end

class Question< ApplicationRecord
  belongs_to :survey
end

<%= nested_form_for @survey do |f| %>
  <%= f.label :title %>
  <%= f.text_field :title %>

  <%= f.fields_for :questions do |question_form| %>
    <%= question_form.label :content, "Question" %>
    <%= question_form.text_field :content %>
    <%= question_form.link_to_remove "Remove Question" %>
  <% end %>

  <%= f.link_to_add "Add Question", :questions %>
  <%= f.submit %>
<% end %>

class SurveysController< ApplicationController
  def new
    @survey = Survey.new
    @survey.questions.build
  end

  def create
    @survey = Survey.new(survey_params)
    if @survey.save
      redirect_to @survey
    else
      render :new
    end
  end

  private

  def survey_params
    params.require(:survey).permit(:title, questions_attributes: [:id, :content, :_destroy])
  end
end