I've stepped through the test case listed in the description on both xenial and bionic with the following package versions:
xenial: xdg-desktop-portal-gtk=1.0.2-0ubuntu0.0 xdg-desktop-portal=1.0.3-0ubuntu0.0 bionic: xdg-desktop-portal-gtk=1.0.2-0ubuntu1.1 xdg-desktop-portal=1.0.3-0ubuntu0.2
I've stepped through the test case listed in the description on both xenial and bionic with the following package versions:
xenial: portal- gtk=1.0. 2-0ubuntu0. 0 portal= 1.0.3-0ubuntu0. 0 portal- gtk=1.0. 2-0ubuntu1. 1 portal= 1.0.3-0ubuntu0. 2
xdg-desktop-
xdg-desktop-
bionic:
xdg-desktop-
xdg-desktop-