code: function (line, block) {
      if (!block.template) {
          return;
      }
  
      var regex = getRegExp(block.template);
      var match = regex.exec(line);
      return match ? match[1] : match;
  }
docs: Parse the file name from the line if it exists.
  @param {string} line - A line from the file.
  @param {Block} block - The replacement block object.
  @returns {string} The file name if it exists.