# declare objects
s = SequenceObject('s:Caller')
w = SequenceObject(':Switch')
c = Placeholder()
r = SequenceObject('r:Caller')
diagram = SequenceDiagram([s, w, c, r])
diagram.setParam('objectSpacing', 0.5)
diagram.step()
w.active()
diagram.async()
s.message(w, 'liftReceiver')
diagram.sync()
w.message(s, 'setDialTone()')
diagram.async()
s.message(w, '*dialDigit(d)')
w.lconstraint('{dialing.executionTime < 30s}')
w.callMethod(w, 'routeCalls(s,n)')
w.createInstance(c, 'c:Convers')
c.active()
c.pushMethod(r, 'ring()')
diagram.async()
r.message(c, 'liftReceiver')
diagram.sync()
c.message(w, 'connect(r,s)')
w.message(s, 'connect(r)')
w.message(r, '')
