```ruby
class Vigor
  class Summoner
    attr_accessor :id, :name, :profile_icon_id, :level, :revision_date

    def initialize(data)
      @id = data["id"]
      @name = data["name"]
      @profile_icon_id = data["profileIconId"]
      @level = data["summonerLevel"]
      @revision_date = DateTime.strptime(data["revisionDate"].to_s,'%s')
    end

    def mastery_pages
      Vigor.mastery_pages(@id)
    end

    def rune_pages
      Vigor.rune_pages(@id)
    end

    def current_mastery_page
      mastery_pages.find {|page| page.current? }
    end

    def current_rune_page
      rune_pages.find {|page| page.current? }
    end
  end
end
```

Refactor Summoner in preparation for new API calls
user
```ruby
class Vigor
  class Summoner
    attr_accessor :id
    Available_fields = [:name, :profile_icon_id, :level, :revision_date]

    def initialize(data)
      @fields = {}
      add_data(data)
    end

    def add_data(data)
      @id = data["id"]
      @fields[:name] = data["name"]
      @fields[:profile_icon_id] = data["profileIconId"]
      @fields[:level] = data["summonerLevel"]
      @fields[:revision_date] = DateTime.strptime(data["revisionDate"].to_s,'%s')
    end

    def mastery_pages
      Vigor.mastery_pages(@id)
    end

    def rune_pages
      Vigor.rune_pages(@id)
    end

    def current_mastery_page
      mastery_pages.find {|page| page.current? }
    end

    def current_rune_page
      rune_pages.find {|page| page.current? }
    end

    def method_missing(meth)
      if Available_fields.include? meth
        return get_or_fetch_field(meth)
      else
        super
      end
    end

    def get_or_fetch_field(field)
      add_data(Client.get("/summoner/" + @id.to_s)) unless @fields[field]
      @fields[field]
    end
  end
end
```
assistant