code: def handle_command_def(self, line):
          
          cmd, arg, line = self.parseline(line)
          if not cmd:
              return
          if cmd == 'silent':
              self.commands_silent[self.commands_bnum] = True
              return # continue to handle other cmd def in the cmd list
          elif cmd == 'end':
              self.cmdqueue = []
              return 1 # end of cmd list
          cmdlist = self.commands[self.commands_bnum]
          if arg:
              cmdlist.append(cmd+' '+arg)
          else:
              cmdlist.append(cmd)
          # Determine if we must stop
          try:
              func = getattr(self, 'do_' + cmd)
          except AttributeError:
              func = self.default
          # one of the resuming commands
          if func.__name__ in self.commands_resuming:
              self.commands_doprompt[self.commands_bnum] = False
              self.cmdqueue = []
              return 1
          return
docs: Handles one command line during command list definition.