         matched = c.properties.isWhitespace && (c.isASCII || !options.usesASCIISpaces)
       case .word:
         matched = (c.properties.isAlphabetic || c == "_") && (c.isASCII || !options.usesASCIIWord)
-      case .custom(let set):
-        matched = set.any { $0.matches(Character(c), with: options) }
       }
       if isInverted {
         matched.toggle()

    case .verticalWhitespace: return "vertical whitespace"
    case .whitespace: return "<whitespace>"
    case .word: return "<word>"
    case .custom(let set): return "<custom \(set)>"
    }
  }
}

  }
}

extension _CharacterClassModel {
  func withMatchLevel(
    _ level: _CharacterClassModel.MatchLevel
