get_ids({'id_one' => 1, 'id_two' => 2, 'id_three' => 3})

##</code><code>##

get_ids({'id_one','id_two','id_three'})

##</code><code>##

sub get_ids {
    $id_hashref = shift;
    map { print "key $_ exists in the request\n" } (keys %{$id_hashref});
}