def init(extension="css")
      if (extension.eql?("css") || extension.eql?("scss"))
        Richcss::Generators::Template.start([extension])
      else
        puts "Only support css or scss extension, default is css"
      end
    end
def init(extension="css")
      if (extension.eql?("css") || extension.eql?("scss"))
        Richcss::Generators::Template.start([extension])
      else
        puts "Only support css or scss extension, default is css"
      end
    end
elements
 |--- ...
 box
 |--- ...
 parts
 |--- ...