Target map for tab navigation using Webix

There's some form to send. I need to navigate among form's textfields using TAB (key) only. But when I do, after last field I lose my tab-focus, going out of form e.g. to browser url. What I need is to cycle tab-jumps so after skipping last field it enters the first textfield.

first -> ... -> last -> first. Make focus not go somewhere out of form.

This problem should be solved using Webix.

Seems it should be some focus-map