code: function getOptGroup(opts) {
    return {
      tag: 'optgroup',
      attrs: {
        disabled: opts.disabled,
        label: opts.label
      },
      children: opts.options.map(getOption),
      key: opts.label
    };
  }
docs: /*
  
  Example:
  
  {
  label: 'group1',
  options: [
  {value: 'value1', text: 'description1'},
  {value: 'value3', text: 'description3'}
  ]
  }