def debug_mtg_build():
g = MTG()
vidP = g.add_component(g.root, label='P', edge_type='/')
vidL = g.add_component(vidP, label='L', edge_type='/')
vidb = g.add_component(vidL, label='base', edge_type='/')
vidt = g.add_child(vidb, label='top', edge_type='<')
vide = g.insert_parent(vidt, edge_type='<', label='elt1')
