createGuildSticker static method 
    
    
    
  Implementation
  static Future<Sticker> createGuildSticker(Snowflake guildId, String name,
    String description, String tags, Uint8List fileContents) async {
  Dio dio = Dio(DiscordSessionSettings.getOptions);
  var fd = FormData.fromMap({
    "name": name,
    "description": description,
    "tags": tags,
    "file": MultipartFile.fromBytes(fileContents)
  });
  var reply = await dio.post(
      "${DiscordEndpoints.BaseURL}${DiscordEndpoints.Guilds}/${guildId.toString()}${DiscordEndpoints.Stickers}",
      options: Options(contentType: "multipart/form-data"),
      data: fd);
  return Sticker.fromJson(reply.data);
}