String (@NotNull ExternalSystemEvent event) { String prefix = event.getTimestamp() + " " + event.getEventType().name() + " " + event.getRecorderId(); if (event instanceof ExternalUploadFinishedEvent failed) { if (isNotEmpty(failed.getError())) { return prefix + " " + escape(failed.getError()); } return prefix; } else if (event instanceof ExternalUploadSendEvent finished) { String hashedFiles = filesToString(finished.getSuccessfullySentFiles()); String errors = errorsToString(finished.getErrors()); return prefix + " " + finished.getSucceed() + " " + finished.getFailed() + " " + finished.getTotal() + " " + hashedFiles + " " + errors; } else if (event instanceof ExternalSystemErrorEvent error) { return prefix + " " + escape(error.getEvent()) + " " + escape(error.getErrorClass()); } return prefix; }