code: function aggregateCoverage(files) {
    var i, len, file, content, results;
    var resultsObj = getEmptyResultObject();
  
    for (i = 0, len = files.length; i < len; i++) {
      file = files[i];
      content = JSON.parse(fs.readFileSync(file).toString());
      resultsObj = populateCoverage(resultsObj, content);
    }
  
    return resultsObj;
  }
docs: Read multiple coverage files and return aggregated coverage.