def compression_level(val = NULL)
      if null?(val)
        @compression_level || Zlib::BEST_COMPRESSION
      else
        unless val.is_a?(Integer)
          raise InvalidValue.new(:compression_level, "be an Integer")
        end

        unless val.between?(1, 9)
          raise InvalidValue.new(:compression_level, "be between 1-9")
        end

        @compression_level = val
      end
    end
def compression_level(val = NULL)
      if null?(val)
        @compression_level || Zlib::BEST_COMPRESSION
      else
        unless val.is_a?(Integer)
          raise InvalidValue.new(:compression_level, "be an Integer")
        end

        unless val.between?(1, 9)
          raise InvalidValue.new(:compression_level, "be between 1-9")
        end

        @compression_level = val
      end
    end
@!group DSL methods
 --------------------------------------------------

 Set or return the level of compression to use when generating the zipped
 tarball. Default: max compression.

 @example
   compression_level 9

 @param [Fixnum] val
   the compression level to use

 @return [Fixnum]