anchor.diff:      aggregations: [ArtworkAggregation]
       artistID: String
       artistIDs: [String]
  +    artistSeriesID: String
       atAuction: Boolean
       attributionClass: [String]
       before: String
  
positive.code:   artists(page: Int, size: Int): [Artist]
    description: String
    featured: Boolean!
  
    # Unique ID for this artist series
    internalID: ID!
  
negative.code:     aggregations: [ArtworkAggregation]
      artistID: String
      artistIDs: [String]
      artistSeriesID: String
      atAuction: Boolean
      attributionClass: [String]
      before: String
  