title: Is it possible to change tinyMCE custom Toolbar ListBox values after tinymce init
body: <p>Following example is add a custom dropdown to tinyMCE, is it possible to change again after init tinyMCE? for example, after init the tinyMCE, update the list again by another button by different list.
      <a href="https://codepen.io/tinymce/pen/JYwJVr" rel="nofollow noreferrer">https://codepen.io/tinymce/pen/JYwJVr</a></p>
  
  <pre><code>tinymce.init({
    selector: 'textarea',
    height: 500,
    toolbar: 'mybutton',
    menubar: false,
      content_css: [
      '//fonts.googleapis.com/css?family=Lato:300,300i,400,400i',
      '//www.tinymce.com/css/codepen.min.css'],
  
    setup: function (editor) {
      editor.addButton('mybutton', {
        type: 'listbox',
        text: 'My listbox',
        icon: false,
        onselect: function (e) {
          editor.insertContent(this.value());
        },
        values: [
          { text: 'Menu item 1', value: '&amp;nbsp;&lt;strong&gt;Some bold text!&lt;/strong&gt;' },
          { text: 'Menu item 2', value: '&amp;nbsp;&lt;em&gt;Some italic text!&lt;/em&gt;' },
          { text: 'Menu item 3', value: '&amp;nbsp;Some plain text ...' }
        ],
        onPostRender: function () {
          // Select the second item by default
          this.value('&amp;nbsp;&lt;em&gt;Some italic text!&lt;/em&gt;');
        }
      });
    }
  });
  </code></pre>