code: public static DiagnosticType make(String name, CheckLevel level,
                                      String descriptionFormat) {
      return
          new DiagnosticType(name, level, new MessageFormat(descriptionFormat));
    }
docs: Create a DiagnosticType at a given CheckLevel.
  
  @param name An identifier
  @param level Either CheckLevel.ERROR or CheckLevel.WARNING
  @param descriptionFormat A format string
  @return A new DiagnosticType