docs: function handleTemplateCache (options, str) {
    var key = options.filename;
    if (options.cache && exports.cache[key]) {
      return exports.cache[key];
    } else {
      if (str === undefined) str = fs.readFileSync(options.filename, 'utf8');
      var templ = exports.compileStreaming(str, options);
      if (options.cache) exports.cache[key] = templ;
      return templ;
    }
  }