You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: selector.rb
    path of file: ./repos/stackneveroverflow/vendor/bundle/ruby/2.3.0/gems/sass-3.4.24/lib/sass
    
    the code of the file until where you have to start completion: require 'sass/selector/simple'
requir
    
      def unify(sels)
        name =
          case sels.first
          when Universal; :universal
          when Element; sels.first.name
          else
            return [self] + sels unless namespace.nil? || namespace == '*'
            return sels unless sels.empty?
            return [self]
          end