createHrzBarChart() {
    ....
    this.hrzBars = new Chart(ctx, {
      type: 'horizontalBar',
      data: {
        labels: ['S1', 'S2', 'S3', 'S4', 'S5', 'S6', 'S7', 'S8'],
        datasets: [{
          label: 'Online viewers in millions',
          data: [2.5, 3.8, 5, 6.9, 6.9, 7.5, 10, 17],
          backgroundColor: '#ddee44', // array should have same number of elements as number of dataset
          borderColor: '#ddee44',// array should have same number of elements as number of dataset
          borderWidth: 1
        },
        {
          label: 'Offline viewers in millions',
          data: [1.5, 2.8, 4, 4.9, 3.9, 4.5, 7, 12],
          backgroundColor: '#dd1144', // array should have same number of elements as number of dataset
          borderColor: '#dd1144',// array should have same number of elements as number of dataset
          borderWidth: 1
        }]
      },
      ....
    });
  }