array_attribute (Gem::Specification)

    # File lib/rubygems/specification.rb, line 175
      def self.array_attribute(name)
        @@non_nil_attributes << ["@#{name}".intern, []]

        @@array_attributes << name
        @@attributes << [name, []]
        @@default_value[name] = []
        code = %{
          def #{name}
            @#{name} ||= []
          end
          def #{name}=(value)
            @#{name} = Array(value)
          end
        }

        module_eval code, __FILE__, __LINE__ - 9
      end