# File lib/net/ssh/transport/hmac/abstract.rb, line 22
      def mac_length(*v)
        @mac_length = nil if !defined?(@mac_length)
        if v.empty?
          @mac_length = superclass.mac_length if @mac_length.nil? && superclass.respond_to?(:mac_length)
          return @mac_length
        elsif v.length == 1
          @mac_length = v.first
        else
          raise ArgumentError, "wrong number of arguments (#{v.length} for 1)"
        end
      end