constructor(_descriptors, _appliers) {
    this.animation = undefined;
    this.backgroundColor = 'rgba(0,0,0,0.1)';
    this.borderColor = 'rgba(0,0,0,0.1)';
    this.color = '#666';
    this.datasets = {};
    this.devicePixelRatio = (context) => context.chart.platform.getDevicePixelRatio();
    this.elements = {};
    this.events = [
      'mousemove',
      'mouseout',
      'click',
      'touchstart',
      'touchmove'
    ];
    this.font = {
      family: "'Helvetica Neue', 'Helvetica', 'Arial', sans-serif",
      size: 12,
      style: 'normal',
      lineHeight: 1.2,
      weight: null
    };
    this.hover = {};
    this.hoverBackgroundColor = (ctx, options) => getHoverColor(options.backgroundColor);
    this.hoverBorderColor = (ctx, options) => getHoverColor(options.borderColor);
    this.hoverColor = (ctx, options) => getHoverColor(options.color);
    this.indexAxis = 'x';
    this.interaction = {
      mode: 'nearest',
      intersect: true,
      includeInvisible: false
    };
    this.maintainAspectRatio = true;
    this.onHover = null;
    this.onClick = null;
    this.parsing = true;
    this.plugins = {};
    this.responsive = true;
    this.scale = undefined;
    this.scales = {};
    this.showLine = true;
    this.drawActiveElementsOnTop = true;

    this.describe(_descriptors);
    this.apply(_appliers);
  }
Please use the module's default export which provides a singleton instance
Note: class is exported for typedoc