code: def do_global_lock(self, args):
          '''read (or clear) the global lock'''
          if args.purge:
              self.task_master.registry.force_clear_lock()
          else:
              owner = self.task_master.registry.read_lock()
              if owner:
                  heartbeat = self.task_master.get_heartbeat(owner)
                  if 'hostname' in heartbeat:
                      self.stdout.write('{0} ({1})\n'.format(owner,
                                                           heartbeat['hostname']))
                  else:
                      self.stdout.write('{0}\n'.format(owner))
              else:
                  self.stdout.write('(unlocked)\n'f do_global_lock(self, args):
          '''read (or clear) the global lock'''
          if args.purge:
              self.task_master.registry.force_clear_lock()
          else:
              owner = self.task_master.registry.read_lock()
              if owner:
                  heartbeat = self.task_master.get_heartbeat(owner)
                  if 'hostname' in heartbeat:
                      self.stdout.write('{0} ({1})\n'.format(owner,
                                                           heartbeat['hostname']))
                  else:
                      self.stdout.write('{0}\n'.format(owner))
              else:
                  self.stdout.write('(unlocked)\n')
docs: read (or clear) the global lock