<https://www.droidforums.net/threads/ringer-volume-control-based-on-caller.66364/>
<http://schema.org/mainEntityOfPage>
<https://www.droidforums.net/threads/ringer-volume-control-based-on-caller.66364/>
<https://www.droidforums.net/threads/ringer-volume-control-based-on-caller.66364/#post-696159>