​I am using Fedora 23 and documentation I found says that this command should exist:
​

​dnf --quiet --duplicated,

​

But the command does not exist

This is the version I have, which I am not sure how to interpret
dnf --version
1.1.10
  Installed: dnf-0:1.1.10-1.fc23.noarch at 2016-09-02 18:43
  Built    : Fedora Project at 2016-08-18 14:43

  Installed: rpm-0:4.13.0-0.rc1.13.fc23.x86_64 at 2016-09-02 18:43
  Built    : Fedora Project at 2016-04-25 13:50

I need to remove duplicates, what is going on?