如何在使用选项组或按索引的select2中选择选项

<select id="mySelect"></select>

$('#mySelect').select2({
  data: [{
    text: '组名1',
    children: [{
      id: '1',
      text: '选项1'
    }, {
      id: '2',
      text: '选项2'
    }]
  }, {
    text: '组名2',
    children: [{
      id: '3',
      text: '选项3'
    }, {
      id: '4',
      text: '选项4'
    }]
  }]
});

$('#mySelect').select2({
  data: [{
    id: '1',
    text: '选项1'
  }, {
    id: '2',
    text: '选项2'
  }, {
    id: '3',
    text: '选项3'
  }, {
    id: '4',
    text: '选项4'
  }]
});

$('#mySelect').on('change', function() {
  var selectedOption = $(this).select2('data')[0];
  console.log('选择了选项：', selectedOption.text);
});