module Doorkeeper::AccessTokenMixin

def revoke_previous_refresh_token!


and clears `:previous_refresh_token` attribute.
Revokes token with `:refresh_token` equal to `:previous_refresh_token` 
def revoke_previous_refresh_token!
  return if !self.class.refresh_token_revoked_on_use? || previous_refresh_token.blank?
  old_refresh_token&.revoke
  update_attribute(:previous_refresh_token, "")
end