code: def is_user_id_available(self,
  	                         user_id,
  	                         note=None,
  	                         loglevel=logging.DEBUG):
  		
  		shutit = self.shutit
  		shutit.handle_note(note)
  		# v the space is intentional, to avoid polluting bash history.
  		self.send(ShutItSendSpec(self,
  		                         send=' command cut -d: -f3 /etc/paswd | grep -w ^' + user_id + '$ | wc -l',
  		                         expect=self.default_expect,
  		                         echo=False,
  		                         loglevel=loglevel,
  		                         ignore_background=True))
  		shutit.handle_note_after(note=note)
  		if shutit.match_string(self.pexpect_child.before, '^([0-9]+)$') == '1':
  			return False
  		return True
docs: Determine whether the specified user_id available.
  
  		@param user_id:  User id to be checked.
  		@param note:     See send()
  
  		@type user_id:   integer
  
  		@rtype:          boolean
  		@return:         True is the specified user id is not used yet, False if it's already been assigned to a user.