title: how to set the buttons size inside a spinner in kivy?
body: <p>kindly need to know how to change or control the size of the special buttons inside a kivy spinner. note: my spinner is in the kv language and not in python and looks like this:</p>
  
  <pre><code>Spinner:
      id:some_id
      text:"some text"
      values:("1","2","3")
      size_hint:(None,None)
      size: root.width/4,root.height/12
  </code></pre>