title: Check if RadioButton is NOT selected
body: <p>I have this logic in my code</p>
  
  <p><code>if(r40.isChecked()){
       //do this
   }</code></p>
  
  <p>It works great, but I needed the negative, "if rb.isNotChecked" or ".isChecked() = false"</p>
  
  <p>But I cant see to find it, also I can't use the RadioGroup because all my RadioButtons are not inside one, I'm controlling them manually</p>