if (Grob *beam = Stem::get_beam (stems[side]))
(void) beam->get_property ("quantized-positions");
poss[side] = stems[side]->extent (stems[side], Y_AXIS)[get_grob_direction (stems[side])]
if (Grob *beam = Stem::get_beam (stems[side]))
(void) beam->get_property ("quantized-positions");
poss[side] = stems[side]->extent (stems[side], Y_AXIS)[get_grob_direction (stems[side])]