title: Parse anonymous login (Guest user)
body: <p>I am making a mobile app using Flutter sdk, which requires me to allow a guest user enter into pages wihtout login id.
  So, I am seeking something like anonymous user login or auto-generate a user with random username.
  I am using <a href="https://pub.dev/packages/parse_server_sdk" rel="nofollow noreferrer">parse_server_sdk</a>.</p>
  <p>In the <a href="https://pub.dev/documentation/parse_server_sdk/latest/flutter_parse_sdk/ParseUser/loginAnonymous.html" rel="nofollow noreferrer">api documentation</a>, I found a function called loginAnonymous() in class ParseUser.
  But the class constructor itself requires username &amp; password for instantiation.</p>
  <p>So, it defeats the purpose of my use-case.
  Please let me know how to get around this problem.</p>