title: strong parameters permit all attributes for nested attributes
body: <p>Is there a way in <a href="https://github.com/rails/strong_parameters" rel="noreferrer">strong parameters</a> to permit all attributes of a <strong>nested_attributes model</strong>?  Here is a sample code.</p>
  
  <pre><code>class Lever &lt; ActiveRecord::Base
   has_one :lever_benefit
   accepts_nested_attributes_for :lever_benefit
  end
  
  class LeverBenefit &lt; ActiveRecord::Base
    # == Schema Information
    #  id          :integer          not null, primary key
    #  lever_id    :integer
    #  explanation :text
  end
  </code></pre>
  
  <p><strong>For lever strong parameters i am writing currently this</strong></p>
  
  <pre><code>def lever
   params.require(:lever).permit(:name,:lever_benefit_attributes =&gt; [:lever_id, :explanation])
  end
  </code></pre>
  
  <p>Is there a way for <strong>nested attributes</strong> i can write to permit all attributes without explicitly giving the attributes name like <code>lever_id</code> and <code>explanation</code> ?</p>
  
  <p><strong>Note</strong>: Please don't get confused with this question with <code>permit!</code> or <code>permit(:all)</code> this is for <strong>permitting all for nested attributes</strong></p>