def contents(custom_binding = nil)
      return @contents unless @contents.nil?

      @contents = File.read(path)
      if path.extname == '.erb'
        @contents = ERB.new(@contents, nil, '>').result(custom_binding ? custom_binding : binding)
      end
      @contents
    end
def contents(custom_binding = nil)
      return @contents unless @contents.nil?

      @contents = File.read(path)
      if path.extname == '.erb'
        @contents = ERB.new(@contents, nil, '>').result(custom_binding ? custom_binding : binding)
      end
      @contents
    end
Reads the contents of the effective robots.txt file
 @return [String] the contents of the effective robots.txt file