Although some of the APIs have been implemented,
adding the below missing one:
check_token_existence(): to validate a v3 token head
Change-Id: I0b95a19162456cbaf524ea6691e7e28c151c6ada
Co-Authored-By: Pradeep Kumar <pk5294@att.com>
Co-Authored-By: Nishant Kumar <nk613n@att.com>
Closes-Bug: #1691044