use Data::Dumper;
sub handle {
  my($data)=@_;

  if($data->{change} eq "empty") {
    print "empty workspace!!\n";
    my $switched; $switched = $i3->command("workspace 1")->cb(sub {
        my( $reply ) = @_;
        print "Switched back to workspace 1\n";
        undef $switched;
        use Data::Dumper;
        print Dumper $reply;
    });
  }
}