How to use karma-coverage - 2 common examples

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
  };

var CoverageReporter = function (rootConfig, helper, logger, emitter) {
  var log = logger.create('coverage');

  // Instance variables
  // ------------------

  this.adapters = [];

  // Options
  // -------

  var config = rootConfig.coverageReporter || {};
  var basePath = rootConfig.basePath;
  var reporters = config.reporters;
  var sourceCache = globalSourceCache.get(basePath);
  var includeAllSources = config.includeAllSources === true;

  var aggregator = config.browserId || 'id'; // ADDED BY KARMA-SHARDING

  if (config.watermarks) {
    config.watermarks = helper.merge({}, istanbul.config.defaultConfig().reporting.watermarks, config.watermarks);
  }

  if (!helper.isDefined(reporters)) {
    reporters = [config];
  }

  var collectors;
  var pendingFileWritings = 0;
  var fileWritingFinished = function () {};