def METHOD_NAME():
  bbox = Bbox( (0,0,0), (1,1,1), dtype=np.float32)
  assert not bbox.subvoxel()
  assert not bbox.empty()
  bbox.maxpt[:] *= -1
  bbox.maxpt.z = 20
  # pathological case
  assert not (bbox.volume() < 1)
  assert bbox.subvoxel()
  assert bbox.empty()
  bbox = Bbox( (1,1,1), (1,1,1) )
  assert bbox.empty()
  bbox = Bbox( (0,0,0), (0.9, 1.0, 1.0) )
  assert bbox.subvoxel()
  assert not bbox.empty()