# File lib/net/ssh/transport/hmac/abstract.rb, line 34
      def digest_class(*v)
        @digest_class = nil if !defined?(@digest_class)
        if v.empty?
          @digest_class = superclass.digest_class if @digest_class.nil? && superclass.respond_to?(:digest_class)
          return @digest_class
        elsif v.length == 1
          @digest_class = v.first
        else
          raise ArgumentError, "wrong number of arguments (#{v.length} for 1)"
        end
      end