anchor.diff:  
     ExceptionResult({
       @required this.filePath,
  +    @required this.fileContentMap,
       @required this.fileContent,
       @required this.exception,
       @required this.contextKey,
  
positive.code:       stackTrace = state.stackTrace;
        contextKey = state.contextKey;
      }
      CaughtException caught = CaughtException(exception, stackTrace);
      String fileContent = _fsState.getFileForPath(path).content;
      _exceptionController.add(
        ExceptionResult(
          filePath: path,
          fileContent: fileContent,
          exception: caught,
          contextKey: contextKey,
        ),
  
negative.code: 
  /// Exception that happened during analysis.
  class ExceptionResult {
    /// The path of the library being analyzed when the [exception] happened.
    ///
    /// Absolute and normalized.
    final String filePath;
  
    /// The content of the library and its parts.
    final Map<String, String> fileContentMap;
  
    /// The path of the file being analyzed when the [exception] happened.
    @Deprecated('Use fileContentMap instead')
    final String fileContent;
  
    /// The exception during analysis of the file with the [filePath].
    final CaughtException exception;
  
    /// If the exception happened during a file analysis, and the context in which
  