samba - Jan 2015 - Adding and removing users to groups - where is the audit trail

Folks, 

I am fairly new to Samba 4 so excuse my lame question.  Am trying to find
out where and how we can log account management activities on Samba 4.  For
example, domain admin adds an account to the domain admin groups or domain
admin disables an account due to employment separation.  I can?t find any
record of this activity on any logs.  Am I missing something?

Thanks.