MimeAppsListFile.setAddedAssocations

        MimeAppsListFile appsList = new MimeAppsListFile();
        appsList.removeAssociation("text/plain", "geany.desktop");
        assert(appsList.removedAssociations() !is null);
        assert(appsList.removedAssociations().appsForMimeType("text/plain").equal(["geany.desktop"]));

        appsList.removeAssociation("image/png", null);
        assert(!appsList.removedAssociations().contains("image/png"));

        string contents =
`[Default Applications]
text/plain=geany.desktop
[Added Associations]
text/plain=emacs.desktop;geany.desktop;kde4-kate.desktop;`;

        appsList = new MimeAppsListFile(iniLikeStringReader(contents));
        appsList.removeAssociation("text/plain", "geany.desktop");
        assert(appsList.removedAssociations().appsForMimeType("text/plain").equal(["geany.desktop"]));
        assert(appsList.addedAssociations().appsForMimeType("text/plain").equal(["emacs.desktop", "kde4-kate.desktop"]));
        assert(!appsList.defaultApplications().contains("text/plain"));

        contents =
`[Added Associations]
text/plain=geany.desktop;`;

        appsList = new MimeAppsListFile(iniLikeStringReader(contents));
        appsList.removeAssociation("text/plain", "geany.desktop");
        assert(appsList.removedAssociations().appsForMimeType("text/plain").equal(["geany.desktop"]));
        assert(!appsList.addedAssociations().contains("text/plain"));