How to use the vega-scenegraph.CanvasHandler function in vega-scenegraph

export default function View(spec) {
  Dataflow.call(this);

  this._el = null;
  this._renderType = CANVAS;
  this._loadConfig = {};
  this._scenegraph = new Scenegraph();
  var root = this._scenegraph.root;

  // initialize renderer and handler
  this._renderer = null;
  this._handler = new CanvasHandler().scene(root);
  this._queue = null;
  this._eventListeners = [];

  // initialize dataflow graph
  var ctx = runtime(this, spec);
  self.context = ctx; // DEBUG
  this._signals = ctx.signals;
  this._scales = ctx.scales;
  this._data = ctx.data;

  // initialize scenegraph
  if (ctx.root) ctx.root.set(root);
  this.pulse(
    this._data.root.input,
    this.changeset().insert(root.items)
  );

Dataflow.call(view);
  if (options.loader) view.loader(options.loader);
  if (options.logger) view.logger(options.logger);
  if (options.logLevel != null) view.logLevel(options.logLevel);

  view._el = null;
  view._elBind = null;
  view._renderType = options.renderer || RenderType.Canvas;
  view._scenegraph = new Scenegraph();
  var root = view._scenegraph.root;

  // initialize renderer, handler and event management
  view._renderer = null;
  view._tooltip = options.tooltip || defaultTooltip,
  view._redraw = true;
  view._handler = new CanvasHandler().scene(root);
  view._preventDefault = false;
  view._timers = [];
  view._eventListeners = [];
  view._resizeListeners = [];

  // initialize dataflow graph
  var ctx = runtime(view, spec, options.functions);
  view._runtime = ctx;
  view._signals = ctx.signals;
  view._bind = (spec.bindings || []).map(function(_) {
    return {
      state: null,
      param: extend({}, _)
    };
  });

export default function View(spec, options) {
  options = options || {};

  Dataflow.call(this);
  this.loadOptions(options.loadOptions || {});
  this.logLevel(options.logLevel || 0);

  this._el = null;
  this._renderType = options.renderer || Canvas;
  this._scenegraph = new Scenegraph();
  var root = this._scenegraph.root;

  // initialize renderer and handler
  this._renderer = null;
  this._handler = new CanvasHandler().scene(root);
  this._queue = null;
  this._eventListeners = [];

  // initialize dataflow graph
  var ctx = runtime(this, spec);
  this._signals = ctx.signals;
  this._scales = ctx.scales;
  this._data = ctx.data;

  // DEBUG - remove later
  if (typeof self !== 'undefined') self.context = ctx;

  // initialize scenegraph
  if (ctx.root) ctx.root.set(root);
  root.source = this._data.root.input;
  this.pulse(

export default function View(spec) {
  Dataflow.call(this);

  this._el = null;
  this._renderType = CANVAS;
  this._loadConfig = {};
  this._scenegraph = new Scenegraph();
  var root = this._scenegraph.root;

  this._renderer = null;
  this._handler = new CanvasHandler().scene(root);
  this._queue = null;
  this._eventListeners = [];

  // initialize dataflow graph
  var ctx = runtime(this, spec);
  this._signals = ctx.signals;
  this._data = ctx.data;

  // initialize scenegraph
  if (ctx.root) ctx.root.set(root);
  this.pulse(
    this._data.root.input,
    changeset().insert(root.items)
  );

  // background color

Dataflow.call(view);
  if (options.loader) view.loader(options.loader);
  if (options.logger) view.logger(options.logger);
  if (options.logLevel != null) view.logLevel(options.logLevel);

  view._el = null;
  view._elBind = null;
  view._renderType = options.renderer || RenderType.Canvas;
  view._scenegraph = new Scenegraph();
  var root = view._scenegraph.root;

  // initialize renderer, handler and event management
  view._renderer = null;
  view._tooltip = options.tooltip || defaultTooltip,
  view._redraw = true;
  view._handler = new CanvasHandler().scene(root);
  view._preventDefault = false;
  view._timers = [];
  view._eventListeners = [];
  view._resizeListeners = [];

  // initialize event configuration
  view._eventConfig = initializeEventConfig(spec.eventConfig);

  // initialize dataflow graph
  var ctx = runtime(view, spec, options.functions);
  view._runtime = ctx;
  view._signals = ctx.signals;
  view._bind = (spec.bindings || []).map(function(_) {
    return {
      state: null,
      param: extend({}, _)

var view = this;
  options = options || {};

  Dataflow.call(view);
  view.loader(options.loader || view._loader);
  view.logLevel(options.logLevel || 0);

  view._el = null;
  view._renderType = options.renderer || RenderType.Canvas;
  view._scenegraph = new Scenegraph();
  var root = view._scenegraph.root;

  // initialize renderer, handler and event management
  view._renderer = null;
  view._redraw = true;
  view._handler = new CanvasHandler().scene(root);
  view._eventListeners = [];
  view._preventDefault = false;
  view._resizeListeners = []

  // initialize dataflow graph
  var ctx = runtime(view, spec, options.functions);
  view._runtime = ctx;
  view._signals = ctx.signals;
  view._bind = (spec.bindings || []).map(function(_) {
    return {
      state: null,
      param: extend({}, _)
    };
  });

  // initialize scenegraph