code: function ErrorManager(generator, config, logger, fileManager) {
          this._generator = generator;
          this._config = config;
          this._logger = logger;
  
          this._fileManager = fileManager;
  
          this._errors = {};
          this._errorsAdded = {};
          this._errorsRemoved = false;
      }
docs: Manage a collection of user-reportable errors, each associated with a paricular source object (layer, layer comp,
  or document)
  
  @constructor
  @param {Generator} generator
  @param {object} config
  @param {Logger} logger
  @param {FileManager} fileManager