# File lib/fog/core/attributes.rb, line 169
      def requires(*args)
        missing = missing_attributes(args)
        if missing.length == 1
          raise(ArgumentError, "#{missing.first} is required for this operation")
        elsif missing.any?
          raise(ArgumentError, "#{missing[0...-1].join(", ")} and #{missing[-1]} are required for this operation")
        end
      end