Why is Mueller not interviewing Hillary, McCain about the dossier? It's related to RUSSIA

Why is Mueller not interviewing Hillary, McCain about the dossier? It's related to RUSSIA

Related:

100% Proof! Russian Collusion was a Hoax Designed to Impeach Trump and Divert Attention from Internal Email Leak & Clinton Criminal Activities:

http://trumpisright.blogspot.com/2017/07/ex-trump-adviser-on-firestorm-over.html