def vendor(val = NULL)
      if null?(val)
        @vendor || "Omnibus <omnibus@getchef.com>"
      else
        unless val.is_a?(String)
          raise InvalidValue.new(:vendor, "be a String")
        end

        @vendor = val
      end
    end
def vendor(val = NULL)
      if null?(val)
        @vendor || "Omnibus <omnibus@getchef.com>"
      else
        unless val.is_a?(String)
          raise InvalidValue.new(:vendor, "be a String")
        end

        @vendor = val
      end
    end
Set or return the vendor who made this package.

 @example
   vendor "Seth Vargo <sethvargo@gmail.com>"

 @param [String] val
   the vendor who make this package

 @return [String]
   the vendor who make this package