Remove search_by_id() from frameline. - frameline is only responsible for drawing a row of frames. - layers and scenes are managed by MBScene_dom. So, function of search_by_id() must move to MBScene_dom class. - onCellClick() and _change_active_frame() are responsible for handling GUI event. - It should not be used with workaround to implement some function. - Solutions - MBScene_dom.find_layer_n_scene_of_nod() is used to replace search_by_id(). - MBScene_framelines.active_frame() is used to replace the workaround.

<inkscape-extension>
    <name>Convert to Symbol</name>
    <id>MadButterfly.ConvertSymbol</id>
	<dependency type="executable" location="extensions">AssignSymbol.py</dependency>
	<dependency type="executable" location="extensions">inkex.py</dependency>
    <effect>
		<object-type>group</object-type>
		<effects-menu>
			<submenu _name="MadButterfly"/>
		</effects-menu>
    </effect>
    <script>
        <command reldir="extensions" interpreter="python">AssignSymbol.py</command>
    </script>
</inkscape-extension>