def test_add_axe():
g = MTG()
labels = g.property('label')
p1 = add_plant(g)
p2 = add_plant(g)
vid_axe = add_axe(g, 'T0')
assert g.complex(vid_axe) == p1
assert labels[g.parent(vid_axe)] == 'MS'
vid_axe = add_axe(g, 'T1.3', plant_number=2)
assert g.complex(vid_axe) == p2
assert labels[g.parent(vid_axe)] == 'T1'
vid_metamer0 = g.component_roots_at_scale(vid_axe, 3)[0]
assert labels[g.parent(vid_metamer0)] == "metamer3"
