List<Error> errorsForFile = e.getValue();

                StringBuilder sb = new StringBuilder();
                for (Error error : errorsForFile) {
                    sb.append("ERROR: " + file.getName() + ":" + error.lineNumber + " " + error.message + "\n    " + error.line + "\n");
                }
                String message = sb.toString();
                getLogger().error(message);
                fw.println(message);