message: Ensure `edition_of` is never an empty string
  While testing something unrelated I ran across an invariant issue where `edition_of` returned an empty string.
diff: @@ -115,7 +115,7 @@ export class ArtworkTombstone extends React.Component<ArtworkTombstoneProps, Art
  <Serif color="black60" size="3t">
  {Constants.CurrentLocale === "en_US" ? artwork.dimensions.in : artwork.dimensions.cm}
  </Serif>
  - {artwork.edition_of && (
  + {!!artwork.edition_of && (
  <Serif color="black60" size="3t">
  {artwork.edition_of}
  </Serif>
  