Error nested exception is java.lang.NullPointerException when calling somet

Vaadin 6 / 7 / 8
1

Hey!
I’ve a question, I always get a “Constructor threw exception; nested exception is java.lang.NullPointerException”
Error: https://pastebin.com/N8NKyjZU

DiscordOAuth2User class:
https://pastebin.com/0xMViwbe

DiscordUser class:
https://pastebin.com/2cqVRunw

StoreView:
https://pastebin.com/mVbGG6Ev

I am able to call everything in DiscordOAuth2User#
But when I call a class for example DiscordOAuth2User#getDiscordUser# it show that error someone knows why?