在初始化Libgdx中的UNNotificationAttachment类时，Objective-C初始化方法返回nil

- (UNNotificationAttachment *)createNotificationAttachmentWithFilePath:(NSString *)filePath {
    if (!filePath || ![filePath isKindOfClass:[NSString class]]) {
        NSLog(@"Invalid file path");
        return nil;
    }

    if (![[NSFileManager defaultManager] fileExistsAtPath:filePath]) {
        NSLog(@"File does not exist at path: %@", filePath);
        return nil;
    }

    NSError *error = nil;
    BOOL isReadable = [[NSFileManager defaultManager] isReadableFileAtPath:filePath];
    if (!isReadable) {
        NSLog(@"Cannot read file at path: %@", filePath);
        return nil;
    }

    NSString *fileExtension = [filePath pathExtension];
    if (![fileExtension isEqualToString:@"jpg"] && ![fileExtension isEqualToString:@"png"]) {
        NSLog(@"Unsupported file format: %@", fileExtension);
        return nil;
    }

    UNNotificationAttachment *attachment = [UNNotificationAttachment attachmentWithIdentifier:@"imageAttachment"
                                                                                   URL:[NSURL fileURLWithPath:filePath]
                                                                               options:nil
                                                                                 error:&error];
    if (error) {
        NSLog(@"Error creating notification attachment: %@", error);
        return nil;
    }

    return attachment;
}