如何自定义chart.js工具提示？两个标签具有相同的数据，我想向您显示每个数据

var chartData = {
  labels: ['标签1', '标签2', '标签3'],
  datasets: [{
    label: '数据集1',
    data: [10, 20, 30],
    backgroundColor: 'rgba(255, 99, 132, 0.2)',
    borderColor: 'rgba(255, 99, 132, 1)',
    borderWidth: 1
  }, {
    label: '数据集2',
    data: [15, 25, 35],
    backgroundColor: 'rgba(54, 162, 235, 0.2)',
    borderColor: 'rgba(54, 162, 235, 1)',
    borderWidth: 1
  }]
};

var chartOptions = {
  tooltips: {
    callbacks: {
      label: function(tooltipItem, data) {
        var datasetLabel = data.datasets[tooltipItem.datasetIndex].label || '';
        var dataPoint = data.datasets[tooltipItem.datasetIndex].data[tooltipItem.index];
        return datasetLabel + ': ' + dataPoint;
      }
    }
  }
};

var chart = new Chart(document.getElementById('myChart'), {
  type: 'bar',
  data: chartData,
  options: chartOptions
});