# File lib/rbrainz/webservice/filter.rb, line 150
      def initialize(filter)
        Utils.check_options filter, 
          :limit, :offset, :query, :title, :discid, :artist, :artistid, 
          :releasetypes, :count, :date, :asin, :lang, :script, :cdstubs
        super(filter)
        @filter[:title]        = filter[:title]     if filter[:title]
        @filter[:discid]       = filter[:discid]    if filter[:discid]
        @filter[:artist]       = filter[:artist]    if filter[:artist]
        @filter[:artistid]     = filter[:artistid]  if filter[:artistid]
        @filter[:count]        = filter[:count]     if filter[:count]
        @filter[:date]         = filter[:date]      if filter[:date]
        @filter[:asin]         = filter[:asin]      if filter[:asin]
        @filter[:lang]         = filter[:lang]      if filter[:lang]
        @filter[:script]       = filter[:script]    if filter[:script]
        
        @filter[:cdstubs] = filter[:cdstubs] ? 'yes' : 'no'
        
        if releasetypes = filter[:releasetypes]
          if releasetypes.respond_to?(:to_a)
            releasetypes = releasetypes.to_a.map do |type|
              Utils.remove_namespace(type)
            end.join(' ')
          end
          @filter[:releasetypes] = releasetypes
        end
      end