anchor.diff:    static List<FcgiRecordType> get values => Enum.values(FcgiRecordType);
   
     factory FcgiRecordType.fromValue (int value) {
  +    if (value == 0 || value > MAXTYPE.value) {
  +      throw new FcgiUnknownTypeBody(value);
  +    }
       return values[value - 1];
     }
   
  
positive.code: 
    static List<FcgiProtocolStatus> get values => Enum.values(FcgiProtocolStatus);
  
    factory FcgiProtocolStatus.fromValue (int value) {
      return values[value - 1];
    }
  
  }
negative.code:   static List<FcgiRequestRole> get values => Enum.values(FcgiRequestRole);
  
    factory FcgiRequestRole.fromValue (int value) {
      if (value == 0 || value > FILTER.value) {
        throw new FcgiEndRequestBody(1, FcgiProtocolStatus.UNKNOWN_ROLE);
      }
      return values[value - 1];
    }
  
  