String (@NotNull IOException e, @NotNull Request request, boolean includeHeaders) { StringBuilder builder = new StringBuilder(); builder.append("Cannot download '").append(request.getURL()).append("': ").append(e.getMessage()); try { URLConnection connection = request.getConnection(); if (includeHeaders) { builder.append("\n, headers: ").append(connection.getHeaderFields()); } if (connection instanceof HttpURLConnection httpConnection) { builder.append("\n, response: ").append(httpConnection.getResponseCode()).append(' ').append(httpConnection.getResponseMessage()); } } catch (Throwable ignored) { } return builder.toString(); }