How to use the istanbul.Collector function in istanbul

module.exports = function (server, coverageObject) {
	// TODO html-cov etc.
	var report = istanbul.Report.create('text');
	var collector = new istanbul.Collector();

	collector.add(coverageObject);
	report.writeReport(collector);
};

var hook = exports.hook = function (server, coverageObject) {
	var config = server.config.coverage;
	if(config) {
		// TODO html-cov etc.
		var report = istanbul.Report.create('text');
		var collector = new istanbul.Collector();

		collector.add(coverageObject);
		report.writeReport(collector);
	}
};

this.onBrowserStart = function (browser) {
    if (!collectors[browser[aggregator]]) { // ADDED BY KARMA-SHARDING
      collectors[browser[aggregator]] = new istanbul.Collector(); // CHANGE MADE BY KARMA-SHARDING

      if (!includeAllSources) return;

      collectors[browser[aggregator]].add(coverageMap.get()); // CHANGE MADE BY KARMA-SHARDING
    } // ADDED BY KARMA-SHARDING
  };

function Listener(emitter, pluginOptions) {

  this.options = pluginOptions;
  this.collector = new istanbul.Collector();
  this.reporter = new istanbul.Reporter(false, this.options.dir);
  this.validator = new Validator(this.options.thresholds);
  this.reporter.addAll(this.options.reporters)

  emitter.on('sub-suite-end', function(browser, data) {
    if (data && data.__coverage__) {
      this.collector.add(data.__coverage__);
    }
  }.bind(this));

  emitter.on('run-end', function(error) {
    if (!error) {
      this.reporter.write(this.collector, sync, function() {});

      if (!validator.validate(this.collector)) {
        throw new Error('Coverage failed');

function Listener(emitter, pluginOptions) {

  this.options = pluginOptions;
  this.collector = new istanbul.Collector();
  this.reporter = new istanbul.Reporter(false, this.options.dir);
  this.validator = new Validator(this.options.thresholds);
  this.reporter.addAll(this.options.reporters)

  emitter.on('sub-suite-end', function(browser, data) {
    if (data.__coverage__) {
      this.collector.add(data.__coverage__);
    }
  }.bind(this));

  emitter.on('run-end', function(error) {
    if (!error) {
      this.reporter.write(this.collector, sync, function() {});

      if (!validator.validate(this.collector)) {
        throw new Error('Coverage failed');

.then(function (coverage) {
            var reporter = istanbul.Report.create("lcov");
            var collector = new istanbul.Collector();

            collector.add(coverage);

            console.log("Writing coverage reports.");
            reporter.writeReport(collector);
        });
    })

runner.on('end', () => {
    const cov = global.__coverage__ || {};
    const collector = new istanbul.Collector();

    collector.add(cov);

    reporters.forEach((reporter) => {
      istanbul.Report.create(reporter, reporterOpts).writeReport(collector, true);
    });
  });
};

function combine(output: string): void {
  const collector = new istanbul.Collector();
  const coveragePaths = ['kernel', 'runtime', 'jit']
    .map(p => join(project.coverage.path, p, 'coverage-final.json'));

  for (const coveragePath of coveragePaths) {
    if (existsSync(coveragePath)) {
      const json = JSON.parse(readFileSync(coveragePath, 'utf8'));
      collector.add(json);
    }
  }
  istanbul.Report.create(output, opts).writeReport(collector);
}

config.onPrepare = _.wrap(config.onPrepare, function(onPrepare) {
  onPrepare();
  protractor.collector = new istanbul.Collector();
});

function (options) {
		this.__super();

		log4js.setGlobalLogLevel('INFO');
		this._options = options || {};

		this._taskDecoratorList = {};
		this._clientDecoratorList = {};
		this._taskList = {};

		this._reportManager = null;

		this._coverageCollector = new istanbul.Collector();

		this.initialize();
	},