title: rails, simple_form, how to set default selected item in radiobuttons
body: <p>how to make 'true' as default here ?</p>
  
  <p><strong>selected: true</strong> option is not working</p>
  
  <pre><code>&lt;%= f.input :smoke, label: "Smoke", :collection =&gt; [[true, "You can"], [false, "You can't"]],
           label_method: :last, value_method: :first, as: :radio_buttons, selected: true %&gt;
  </code></pre>