title: Bidirectional bind between a boolean property and two RadioButtons
body: <p>I have a class, Person, with a boolean property named 'genre' whose value will
  be true for a boy or false for a girl.</p>
  
  <p>I need to create a bidirectional bind between Person.genre and two RadioButtons
  so that when I person object is populated with data from a data source the
  RadioButtons will be set accordingly (Male RadioButton checked if Person.genre
  is true, Female RadioButton checked if <code>Person.genre</code> is false) or if user clicks
  Male RadioButton Person.genre will be set as true, if user clicks Female
  RadioButton <code>Person.genre</code> will be set as false.</p>
  
  <p>Please, help me in getting the most appropriate practice with that: should
  I use <code>Bindings API</code>, <code>RadioButton.bindBidirectional</code> method with
  <code>Person.genreProperty()</code> or the opposite, or even use a change listener???</p>
  
  <p>Best regards,
  Romualdo.</p>