required_segment_keys

# File actionpack/lib/action_controller/routing/route.rb, line 39
      def required_segment_keys
        required_segments = segments.select {|seg| (!seg.optional? && !seg.is_a?(DividerSegment)) || seg.is_a?(PathSegment) }
        required_segments.collect { |seg| seg.key if seg.respond_to?(:key)}.compact
      end