How to use the klampt.vis.unlock function in Klampt

vis.setPlugin(program)
	program.reshape(800,600)
	vis.show()
	while vis.shown():
		time.sleep(0.1)
	return
	
	#this code manually updates the vis
	vis.add("world",world)
	vis.show()
	t0 = time.time()
	while vis.shown():
		vis.lock()
		sim.simulate(0.01)
		sim.updateWorld()
		vis.unlock()
		t1 = time.time()
		time.sleep(max(0.01-(t1-t0),0.001))
		t0 = t1
	return

vis.setPlugin(program)
	vis.show()
	while vis.shown():
		time.sleep(0.1)
	return
	"""
	
	#this code manually updates the visualization
	vis.add("world",world)
	vis.show()
	t0 = time.time()
	while vis.shown():
		vis.lock()
		sim.simulate(0.01)
		sim.updateWorld()
		vis.unlock()
		t1 = time.time()
		time.sleep(max(0.01-(t1-t0),0.001))
		t0 = t1
	return

vis.setPlugin(program)
	vis.show()
	while vis.shown():
		time.sleep(0.1)
	return
	"""

	#this code manually updates the visualization
	vis.add("world",world)
	vis.show()
	t0 = time.time()
	while vis.shown():
		vis.lock()
		sim.simulate(0.01)
		sim.updateWorld()
		vis.unlock()
		t1 = time.time()
		time.sleep(max(0.01-(t1-t0),0.001))
		t0 = t1
	return