userID property
User ID, a string with a maximum length of 32 bytes or less. It is customized by the developer. Only support numbers, English characters and '!', '#', '$', '%', '&', '(', ')', '+', '-', ':', ';', '<', '=', '.', '>', '?', '@', '', '', '^', '_', '{', '}', '|', '~'.
Implementation
String userID;