def _fill_middle_box(self, box):
        """
        Helper function to fill an box with a label and a button

        @param box: the Gtk.Box to fill
        """
        self.sync_status_label = Gtk.Label()
        self.sync_status_label.set_alignment(xalign=0.8, yalign=0.5)
        self.sync_button = Gtk.Button()
        self.sync_button.connect("clicked", self.on_sync_button_clicked)
        box.pack_start(self.sync_status_label, True, True, 0)
        box.pack_start(self.sync_button, True, True, 0)